Vulnerability database
Every flaw the U.S. government’s cybersecurity agency (CISA) has confirmed attackers are using, plus the new WordPress plugin and theme bugs published each day, sorted by what they mean for a small business. We refresh it twice a day. If you see something your website or office runs, tell us.
167 results · page 1 of 4
Oct 28, 2026wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re-appends a trailing slash to rename source paths, causing renameat onCVE-2026-118688 · Other software · bytecodealliance · reported by VulnCheckHigh 8.8
wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re-appends a trailing slash to rename source paths, causing renameat on macOS and FreeBSD hosts to follow directory symlinks. A guest with sandbox write access can rename a relative symlink such as "up/" to move host directories into its sandbox and read or write them.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comvulncheck.com
Oct 23, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-115893 · Other software · bytecodealliance · reported by GitHubCritical 9.9
Wasmtime is a runtime for WebAssembly. Prior to 36.0.19, 48.0.7, and 49.0.4, the Cranelift compiler backend on aarch64 can compile a Wasm br_table instruction with more than approximately 256,000 targets so that it has an incorrect conditional branch target. The branch can then jump to arbitrary other code at a user-controlled offset, allowing a user-controlled Wasm module to escape the sandbox on aarch64 engines using the default Cranelift backend. This issue is fixed in versions 36.0.19, 48.0.7, and 49.0.4.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 23, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-115892 · Other software · bytecodealliance · reported by GitHubMedium 5.7
Wasmtime is a runtime for WebAssembly. From 46.0.0 until 48.0.7 and 49.0.4, lowering a host-created component-model stream or future into a guest can omit a required payload-type check after the value passes through guest code and returns through StreamAny, FutureAny, Val::Stream, Val::Future, or an equivalent typed reader. A malicious guest that controls exported function types or returned values can cause the host to pass the type-erased value to a guest expecting a different payload type, which panics the Wasmtime host. This issue is fixed in versions 48.0.7 and 49.0.4.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 23, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-115889 · Other software · bytecodealliance · reported by GitHubCritical 9.9
Wasmtime is a runtime for WebAssembly. Prior to 36.0.19 and 43.0.0, the Cranelift compiler backend bit-packs SSA value indices in a way that can silently overflow in release builds when compiling a sufficiently large or specially crafted Wasm function with many SSA values. The overflow can make Cranelift reference incorrect IR values, causing arbitrary miscompilation, type confusion, and other attacker-controlled effects that may escape the Wasm sandbox on any architecture using the default Cranelift backend. This issue is fixed in versions 36.0.19 and 43.0.0.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 22, 2026Wasmtime before 24.0.12, 25.0.0 before 36.0.13, 37.0.0 before 46.0.2, and 47.0.0 before 47.0.3 contains a type confusion vulnerability because several Store APICVE-2026-115393 · Other software · bytecodealliance · reported by VulnCheckLow 1
Wasmtime before 24.0.12, 25.0.0 before 36.0.13, 37.0.0 before 46.0.2, and 47.0.0 before 47.0.3 contains a type confusion vulnerability because several Store APIs fail to validate that objects belong to the Store's Engine. Embedders mixing objects between Engines via Instance::new, StructRefPre::new, or Tag::new can trigger trampoline signature mismatches causing out-of-bounds stack writes, GC heap corruption, or panics.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comvulncheck.com
Oct 22, 2026Wasmtime before 24.0.13, 25.0.0 before 36.0.14, 37.0.0 before 46.0.3, and 47.0.0 before 47.0.4 allows a filesystem sandbox escape in wasmtime-wasi because its cCVE-2026-115392 · Other software · bytecodealliance · reported by VulnCheckHigh 8.8
Wasmtime before 24.0.13, 25.0.0 before 36.0.14, 37.0.0 before 46.0.3, and 47.0.0 before 47.0.4 allows a filesystem sandbox escape in wasmtime-wasi because its cap-std dependency mishandles symlinks with trailing slashes on macOS and Linux kernels lacking openat2. A guest with write access to any sandboxed directory can read and write any host-accessible file, and read-only guests may read host files via preexisting symlinks.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comvulncheck.com
Oct 22, 2026Wasmtime 46.0.0 before 46.0.3 and 47.0.0 before 47.0.4 contains an uncontrolled resource allocation vulnerability in its WASIp3 implementation that buffers guesCVE-2026-115391 · Other software · bytecodealliance · reported by VulnCheckMedium 6.9
Wasmtime 46.0.0 before 46.0.3 and 47.0.0 before 47.0.4 contains an uncontrolled resource allocation vulnerability in its WASIp3 implementation that buffers guest-specified-length writes on the host without limit. Malicious guests can offer large buffers to WASIp3 file or HTTP write streams, causing the host to copy and buffer all bytes, bounded only by guest linear memory, exhausting host memory.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comvulncheck.com
Oct 22, 2026Wasmtime 47.0.0 before 48.0.3 and 49.0.0 before 49.0.1 contains a fuel accounting flaw in Cranelift-compiled call_ref and try_table catch paths.CVE-2026-115390 · Other software · bytecodealliance · reported by VulnCheckMedium 6.9
Wasmtime 47.0.0 before 48.0.3 and 49.0.0 before 49.0.1 contains a fuel accounting flaw in Cranelift-compiled call_ref and try_table catch paths. Malicious guests can reset consumed fuel after calls to run exponentially long on linear fuel, evading timeouts and periodic yields for denial of service.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comvulncheck.com
Oct 22, 2026Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately account for host allocations when lifting guest values through the dCVE-2026-115389 · Other software · bytecodealliance · reported by VulnCheckLow 1
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately account for host allocations when lifting guest values through the dynamically-typed Val API, bypassing the hostcall fuel limit. A malicious WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comvulncheck.com
Oct 22, 2026wasmtime-wasi-http in Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not enforce the wasi:io/streams check-write allowance for WASCVE-2026-115388 · Other software · bytecodealliance · reported by VulnCheckMedium 6.9
wasmtime-wasi-http in Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not enforce the wasi:io/streams check-write allowance for WASIp2 outgoing HTTP bodies, so oversized writes succeed instead of trapping. A malicious guest can pass large buffers to write on outgoing-body resources, holding host allocations for the store's lifetime and exhausting host memory.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comvulncheck.com
Oct 22, 2026Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 contains a denial of service vulnerability in wasmtime-wasi that allows guest WASI progrCVE-2026-115387 · Other software · bytecodealliance · reported by VulnCheckMedium 6.9
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 contains a denial of service vulnerability in wasmtime-wasi that allows guest WASI programs to panic the host via overflowing filesystem timestamps. Attackers can pass atim or mtim values whose sub-second field overflows the seconds field to path_filestat_set_times, fd_filestat_set_times, set-times, or set-times-at, crashing the host.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comvulncheck.com
Oct 22, 2026Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 contains an information disclosure vulnerability in the WASIp1 fd_readdir implementationCVE-2026-115386 · Other software · bytecodealliance · reported by VulnCheckLow 2.1
Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 contains an information disclosure vulnerability in the WASIp1 fd_readdir implementation that copies uninitialized struct padding into guest memory. Guests with a preopened directory can list entries to receive three bytes of leftover host stack or heap memory per directory entry.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comvulncheck.com
Oct 22, 2026Wasmtime 46.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a denial of service vulnerability in the wasmtime-wasi WASIp3 implementation that allows guests CVE-2026-115385 · Other software · bytecodealliance · reported by VulnCheckMedium 6.9
Wasmtime 46.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a denial of service vulnerability in the wasmtime-wasi WASIp3 implementation that allows guests to abort the Unix host process. Guests with mutable preopened directory access can call set-times or set-times-at with negative seconds timestamps before the epoch, triggering an assertion failure that crashes the host.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comvulncheck.com
Oct 22, 2026Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write ~16KB to the native CVE-2026-115384 · Other software · bytecodealliance · reported by VulnCheckCritical 9.4
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write ~16KB to the native stack via unvalidated async callback result types. Attackers can supply components with mistyped component-model-async callback functions to overwrite return addresses, crashing the host or escaping the sandbox.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comvulncheck.com
Oct 22, 2026Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation vulnerability that accepts components whose core modules import WebAssembCVE-2026-115383 · Other software · bytecodealliance · reported by VulnCheckMedium 5.9
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation vulnerability that accepts components whose core modules import WebAssembly tags with a subtype of the original type. Malicious guests can mis-type exception object payloads to corrupt the GC heap, causing Wasmtime to panic when the exceptions proposal is enabled.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comvulncheck.com
Oct 22, 2026Wasmtime 46.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a denial-of-service vulnerability in its wasi:http implementation that allows guests to panic thCVE-2026-115382 · Other software · bytecodealliance · reported by VulnCheckMedium 5.9
Wasmtime 46.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a denial-of-service vulnerability in its wasi:http implementation that allows guests to panic the host. Guests can specify a zero between-bytes-timeout request option, which is forwarded directly to a Tokio API that panics, crashing the host embedding.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comvulncheck.com
Oct 22, 2026Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 contains an unbounded memory allocation in the wasmtime-wasi WASIp2 write-zeroes method CVE-2026-115381 · Other software · bytecodealliance · reported by VulnCheckMedium 5.9
Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 contains an unbounded memory allocation in the wasmtime-wasi WASIp2 write-zeroes method of SinkOutputStream, the default stream used when stdout/stderr are not configured. A malicious WebAssembly guest can request huge zero-filled writes, exhausting host memory and causing denial of service.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comvulncheck.com
Oct 22, 2026Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 contains a denial of service vulnerability in the wasmtime-wasi WASI preview 0 poll_oneoCVE-2026-115380 · Other software · bytecodealliance · reported by VulnCheckMedium 5.1
Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 contains a denial of service vulnerability in the wasmtime-wasi WASI preview 0 poll_oneoff adapter, which performs O(n) host work per subscription without consuming or checking fuel. Malicious guest modules can pass many subscriptions to force long-running host computation that ignores configured fuel limits.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comvulncheck.com
Oct 22, 2026Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a missing GC rooting vulnerability that leaves references live across try_call unrooted when comCVE-2026-115379 · Other software · bytecodealliance · reported by VulnCheckMedium 6.9
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a missing GC rooting vulnerability that leaves references live across try_call unrooted when compiling Wasm modules. Attackers can supply Wasm modules whose callee triggers garbage collection, leaving stale or dangling references that cause GC heap corruption or incorrect execution.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comvulncheck.com
Oct 21, 2026Apache Traffic Server's experimental wasm plugin has a use-after-free in its transaction-close handler and forwards unvalidated guest-supplied metric IDs to theCVE-2026-111804 · Websites & servers · Apache Software Foundation · reported by security@apache.orgHigh 8.8
Apache Traffic Server's experimental wasm plugin has a use-after-free in its transaction-close handler and forwards unvalidated guest-supplied metric IDs to the internal stats API. This issue affects Apache Traffic Server: from 10.0.0 through 10.1.4, 10.2.0. Users are recommended to upgrade to version 10.1.5 or 10.2.1, which fix the issue.
- Product
- Apache Traffic Server
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 15, 2026runwasi facilitates running Wasm and WASI workloads managed by containerd.CVE-2026-47218 · Other software · containerd · reported by GitHubCritical 9.3
runwasi facilitates running Wasm and WASI workloads managed by containerd. Prior to 0.6.1, containerd-shim-wasmtime-v1 can treat Wasmtime precompiled bytes supplied directly in an OCI image layer as a trusted artifact from the precompile-cache path and deserialize them as native code. An attacker who causes a victim to run a crafted image can bypass WebAssembly validation and execute native code in the shim zygote process, gaining the filesystem, environment, credentials, networking, and Linux syscall access available to the workload container. Downstream shims built with runwasi's containerd-shim-wasm precompile-cache API are also affected if they implement Compiler and trust executable precompiled artifacts from OCI image layers; the 0.6.1 boundary applies specifically to containerd-shim-wasmtime and does not independently certify downstream product releases. The flaw escapes the WASI sandbox to the workload container boundary, but it does not by itself bypass container isolation or provide direct host code execution. This issue is fixed in version 0.6.1.
- Product
- runwasi
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 15, 2026A flaw was found in the internal WebAssembly (WASM) shim used by the Kuadrant operator.CVE-2026-108334 · Other software · Red Hat · reported by Red HatHigh 7.4
A flaw was found in the internal WebAssembly (WASM) shim used by the Kuadrant operator. When generating the CEL predicate that determines whether Gateway-level authentication and rate limiting should run, the shim does not correctly escape values from HTTPRoute match fields. A user who can create or modify an HTTPRoute attached to a shared Gateway can provide a crafted path, header, or query match value that causes the predicate to skip those checks. The request is still forwarded to the route’s backend.
- Product
- Red Hat Connectivity Link 1.4
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordaccess.redhat.comaccess.redhat.com
Oct 11, 2026hyper-mcp through 0.8.3 contains a signature verification bypass vulnerability in load_wasm in src/wasm/oci.rs that verifies the Cosign signature of a separatelCVE-2026-108698 · Other software · hyper-mcp-rs · reported by VulnCheckHigh 8.3
hyper-mcp through 0.8.3 contains a signature verification bypass vulnerability in load_wasm in src/wasm/oci.rs that verifies the Cosign signature of a separately resolved tag rather than the loaded manifest. Attackers controlling registry responses for the tag can serve an unsigned malicious manifest to the loader and a signed one to Cosign, executing unsigned WebAssembly plugins with configured host capabilities.
- Product
- hyper-mcp
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 2, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-104855 · Other software · bytecodealliance · reported by GitHubLow 2
Wasmtime is a runtime for WebAssembly. From 46.0.0 until 46.0.2 and 47.0.3, fuel and epoch preemption checks inside bulk operations including memory.copy, table.grow, and array.copy can expose invalid intermediate state when an embedder mutates a Store in Store::epoch_deadline_callback or continues using a Store after cancellation or a trap. A cancelled non-nullable table growth can leave null elements, linear-memory growth during memory.copy can invalidate retained raw pointers, and callback-triggered garbage collection during array.copy can invalidate GC pointers, resulting in a crash, invalid memory access, or GC heap corruption. Embeddings whose callbacks only access the host data in Store<T>, and embeddings that discard a Store after timeout or epoch deadline, are not affected. This issue is fixed in versions 46.0.2 and 47.0.3.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 30, 2026ZeroClaw versions before 0.8.5 built with plugins-wasm feature contain a path traversal vulnerability in plugin installation that fails to validate the wasm_patCVE-2026-101885 · Other software · zeroclaw-labs · reported by VulnCheckHigh 8.5
ZeroClaw versions before 0.8.5 built with plugins-wasm feature contain a path traversal vulnerability in plugin installation that fails to validate the wasm_path manifest field. Attackers can convince users to install crafted plugins that write arbitrary files to paths outside the plugins directory, such as shell startup files, enabling code execution.
- Product
- ZeroClaw
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 30, 2026Kobako is a Ruby gem that embeds a Wasm-isolated mruby interpreter inside applications, allowing execution of untrusted Ruby scripts (LLM-generated code, user fCVE-2026-55107 · Other software · elct9620 · reported by GitHubCritical 10
Kobako is a Ruby gem that embeds a Wasm-isolated mruby interpreter inside applications, allowing execution of untrusted Ruby scripts (LLM-generated code, user formulas, student submissions, third-party plugins) in-process without giving them access to host memory, files, network, or credentials. From version 0.1.0 to before version 0.9.1, a guest mruby script running inside the Kobako sandbox can execute arbitrary Ruby in the host process, fully escaping the sandbox. This issue has been patched in version 0.9.1.
- Product
- kobako
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 12, 2026wasm2c in WebAssembly wabt through 1.0.41 allows sandbox escape in some situations that primarily involve 32-bit platforms, aka a "table flip" attack.CVE-2026-90648 · Other software · WebAssembly · reported by MITREHigh 7.1
wasm2c in WebAssembly wabt through 1.0.41 allows sandbox escape in some situations that primarily involve 32-bit platforms, aka a "table flip" attack. It does not check the return value of calloc() in wasm_rt_allocate_funcref_table() (wasm2c/wasm-rt-impl-tableops.inc). When the funcref table allocation fails, table->data is left NULL while table->size keeps the guest-declared element count; thus, bounds checks still pass and table element accesses resolve to absolute memory addresses (i * sizeof(wasm_rt_funcref_t)). This gives arbitrary read and write of host process memory and - via table.get, table.set, and call_indirect - arbitrary code execution, defeating the isolation that wasm2c exists to provide (a full sandbox escape). wasm2c is used as an in-process sandboxing boundary by RLBox and WasmBoxC, including in Firefox, which compiles the Graphite, Hunspell, Ogg, Expat, and Woff2 libraries via wasm2c to contain untrusted font, media, and XML input. Therefore, sandboxing in these applications is potentially affected. Exploitation requires the funcref table allocation to fail, for example under an address-space limit (RLIMIT_AS), on 32-bit hosts, with vm.overcommit_memory=2, or un
- Product
- wabt
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordblog.mozilla.orgbugzilla.mozilla.org
Jul 8, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-58494 · Other software · bytecodealliance · reported by GitHubMedium 6.5
Wasmtime is a runtime for WebAssembly. Prior to 24.0.11, 36.0.12, 45.0.3, and 46.0.1, wasmtime-wasi hard-link creation and renaming check directory permissions but not matching FilePerms on source and destination preopens, allowing a WASI guest with a read-only source file capability to overwrite host files exposed as FilePerms::READ through wasip1, wasip2, or wasip3 filesystem interfaces. This issue is fixed in versions 24.0.11, 36.0.12, 45.0.3, and 46.0.1.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Jul 1, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-54786 · Other software · bytecodealliance · reported by GitHubLow 2.3
Wasmtime is a runtime for WebAssembly. All versions prior to 24.0.10; versions 25.0.0 through those before 36.0.11; versions 37.0.0 through those before 44.0.3; and versions 45.0.0 and 45.0.1 contain a native implementation of WASIp1 which suffers from a leak in the fd_renumber function where the file descriptor being renumbered to is not properly closed. Wasmtime's implementation erroneously only updated the table of descriptors for WASIp1 and didn't update the underlying table of descriptors used by the host. This behavior means that while fd_renumber works correctly from a guest's perspective it ends up leaking resources in the host that aren't cleaned up until the corresponding Store is destroyed. In a loop, guests can use fd_renumber to cause hosts to exhaust both resources and file descriptors. This bug only affects the native implementation of WASIp1, meaning that only runtimes which load core wasm modules and expose fd_renumber are affected. Runtimes are additionally only affected if they expose the ability to acquire a file descriptor, such as opening a file. For runtimes that deny access to files they are unaffected. This issue has been fixed in versions 24.0.10, 36.0.11
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Jun 15, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-47261 · Other software · bytecodealliance · reported by GitHubHigh 7.5
Wasmtime is a runtime for WebAssembly. In versions prior to 24.0.9, 36.0.10, and 44.0.2, when a filesystem preopen is given DirPerms::all() and FilePerms::READ without FilePerms::WRITE, this access control mechanism can be bypassed via the wasip2 descriptor.open-at or wasip1 path_open interfaces by opening a file with only the OpenFlags::TRUNCATE oflag. The root cause is that the clause handling OpenFlags::TRUNCATE in crates/wasi/src/filesystem.rs (Dir::open_at, lines 967–969) did not set open_mode |= OpenMode::WRITE;, which is later used for the access control check against FilePerms to determine whether opening the file is permitted; the single-line fix adds that missing assignment, after which the affected calls correctly fail with error-code.not-permitted and ERRNO_PERM respectively. Only wasmtime-wasi embeddings that combine DirPerms::MUTATE with FilePerms::READ are affected by this bug. In particular, the Wasmtime project's wasmtime-cli's use of wasmtime-wasi is not affected, because it always sets FilePerms::all() for all preopens. This issue has been fixed in versions 24.0.9, 36.0.10 and44.0.2.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 14, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-44216 · Other software · bytecodealliance · reported by GitHubMedium 5.9
Wasmtime is a runtime for WebAssembly. From 30.0.0 to 36.0.8, 43.0.2, and 44.0.1, Wasmtime's allocation logic for a WebAssembly table contained checked arithmetic which panicked on overflow. This overflow is possible to trigger, and thus panic, when a table with an extremely large size is allocated. This is possible with the WebAssembly memory64 proposal where tables can have sizes in the 64-bit range as opposed to the previous 32-bit range which would not overflow. The panic happens when attempting to create a very large table, such as when instantiating a WebAssembly module or component. This vulnerability is fixed in 36.0.8, 43.0.2, and 44.0.1.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comaccess.redhat.com
Apr 9, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-35195 · Other software · bytecodealliance · reported by GitHubMedium 6.1
Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime's implementation of transcoding strings between components contains a bug where the return value of a guest component's realloc is not validated before the host attempts to write through the pointer. This enables a guest to cause the host to write arbitrary transcoded string bytes to an arbitrary location up to 4GiB away from the base of linear memory. These writes on the host could hit unmapped memory or could corrupt host data structures depending on Wasmtime's configuration. Wasmtime by default reserves 4GiB of virtual memory for a guest's linear memory meaning that this bug will by default on hosts cause the host to hit unmapped memory and abort the process due to an unhandled fault. Wasmtime can be configured, however, to reserve less memory for a guest and to remove all guard pages, so some configurations of Wasmtime may lead to corruption of data outside of a guest's linear memory, such as host data structures or other guests's linear memories. This vulnerability is fixed in 24.0.7, 36.0.7, 42.0.2, and 43.0.1.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 9, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-35186 · Other software · bytecodealliance · reported by GitHubMedium 6.1
Wasmtime is a runtime for WebAssembly. From 25.0.0 to before 36.0.7, 42.0.2, and 43.0.1, Wasmtime's Winch compiler backend contains a bug where translating the table.grow operator causes the result to be incorrectly typed. For 32-bit tables this means that the result of the operator, internally in Winch, is tagged as a 64-bit value instead of a 32-bit value. This invalid internal representation of Winch's compiler state compounds into further issues depending on how the value is consumed. The primary consequence of this bug is that bytes in the host's address space can be stored/read from. This is only applicable to the 16 bytes before linear memory, however, as the only significant return value of table.grow that can be misinterpreted is -1. The bytes before linear memory are, by default, unmapped memory. Wasmtime will detect this fault and abort the process, however, because wasm should not be able to access these bytes. Overall this this bug in Winch represents a DoS vector by crashing the host process, a correctness issue within Winch, and a possible leak of up to 16-bytes before linear memory. Wasmtime's default compiler is Cranelift, not Winch, and Wasmtime's default settings
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 9, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-34988 · Other software · bytecodealliance · reported by GitHubLow 2.3
Wasmtime is a runtime for WebAssembly. From 28.0.0 to before 36.0.7, 42.0.2, and 43.0.1, Wasmtime's implementation of its pooling allocator contains a bug where in certain configurations the contents of linear memory can be leaked from one instance to the next. The implementation of resetting the virtual memory permissions for linear memory used the wrong predicate to determine if resetting was necessary, where the compilation process used a different predicate. This divergence meant that the pooling allocator incorrectly deduced at runtime that resetting virtual memory permissions was not necessary while compile-time determine that virtual memory could be relied upon. The pooling allocator must be in use, Config::memory_guard_size configuration option must be 0, Config::memory_reservation configuration must be less than 4GiB, and pooling allocator must be configured with max_memory_size the same as the memory_reservation value in order to exploit this vulnerability. If all of these conditions are applicable then when a linear memory is reused the VM permissions of the previous iteration are not reset. This means that the compiled code, which is assuming out-of-bounds loads will se
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 9, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-34987 · Other software · bytecodealliance · reported by GitHubCritical 9
Wasmtime is a runtime for WebAssembly. From 25.0.0 to before 36.0.7, 42.0.2, and 43.0.1, Wasmtime with its Winch (baseline) non-default compiler backend may allow properly constructed guest Wasm to access host memory outside of its linear-memory sandbox. This vulnerability requires use of the Winch compiler (-Ccompiler=winch). By default, Wasmtime uses its Cranelift backend, not Winch. With Winch, the same incorrect assumption is present in theory on both aarch64 and x86-64. The aarch64 case has an observed-working proof of concept, while the x86-64 case is theoretical and may not be reachable in practice. This Winch compiler bug can allow the Wasm guest to access memory before or after the linear-memory region, independently of whether pre- or post-guard regions are configured. The accessible range in the initial bug proof-of-concept is up to 32KiB before the start of memory, or ~4GiB after the start of memory, independently of the size of pre- or post-guard regions or the use of explicit or guard-region-based bounds checking. However, the underlying bug assumes a 32-bit memory offset stored in a 64-bit register has its upper bits cleared when it may not, and so closely related va
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 9, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-34983 · Other software · bytecodealliance · reported by GitHubLow 1
Wasmtime is a runtime for WebAssembly. In 43.0.0, cloning a wasmtime::Linker is unsound and can result in use-after-free bugs. This bug is not controllable by guest Wasm programs. It can only be triggered by a specific sequence of embedder API calls made by the host. Specifically, the following steps must occur to trigger the bug clone a wasmtime::Linker, drop the original linker instance, use the new, cloned linker instance, resulting in a use-after-free. This vulnerability is fixed in 43.0.1.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 9, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-34971 · Other software · bytecodealliance · reported by GitHubCritical 9
Wasmtime is a runtime for WebAssembly. From 32.0.0 to before 36.0.7, 42.0.2, and 43.0.1, Wasmtime's Cranelift compilation backend contains a bug on aarch64 when performing a certain shape of heap accesses which means that the wrong address is accessed. When combined with explicit bounds checks a guest WebAssembly module this can create a situation where there are two diverging computations for the same address: one for the address to bounds-check and one for the address to load. This difference in address being operated on means that a guest module can pass a bounds check but then load a different address. Combined together this enables an arbitrary read/write primitive for guest WebAssembly when accesssing host memory. This is a sandbox escape as guests are able to read/write arbitrary host memory. This vulnerability has a few ingredients, all of which must be met, for this situation to occur and bypass the sandbox restrictions. This miscompiled shape of load only occurs on 64-bit WebAssembly linear memories, or when Config::wasm_memory64 is enabled. 32-bit WebAssembly is not affected. Spectre mitigations or signals-based-traps must be disabled. When spectre mitigations are enable
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comaccess.redhat.com
Apr 9, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-34946 · Other software · bytecodealliance · reported by GitHubMedium 5.9
Wasmtime is a runtime for WebAssembly. From 25.0.0 to before 36.0.7, 42.0.2, and 43.0.1, Wasmtime's Winch compiler contains a vulnerability where the compilation of the table.fill instruction can result in a host panic. This means that a valid guest can be compiled with Winch, on any architecture, and cause the host to panic. This represents a denial-of-service vulnerability in Wasmtime due to guests being able to trigger a panic. The specific issue is that a historical refactoring changed how compiled code referenced tables within the table.* instructions. This refactoring forgot to update the Winch code paths associated as well, meaning that Winch was using the wrong indexing scheme. Due to the feature support of Winch the only problem that can result is tables being mixed up or nonexistent tables being used, meaning that the guest is limited to panicking the host (using a nonexistent table), or executing spec-incorrect behavior and modifying the wrong table. This vulnerability is fixed in 36.0.7, 42.0.2, and 43.0.1.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 9, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-34945 · Other software · bytecodealliance · reported by GitHubLow 2.3
Wasmtime is a runtime for WebAssembly. From 25.0.0 to before 36.0.7, 42.0.2, and 43.0.1, Wasmtime's Winch compiler contains a bug where a 64-bit table, part of the memory64 proposal of WebAssembly, incorrectly translated the table.size instruction. This bug could lead to disclosing data on the host's stack to WebAssembly guests. The host's stack can possibly contain sensitive data related to other host-originating operations which is not intended to be disclosed to guests. This bug specifically arose from a mistake where the return value of table.size was statically typed as a 32-bit integer, as opposed to consulting the table's index type to see how large the returned register could be. When combined with details about Wnich's ABI, such as multi-value returns, this can be combined to read stack data from the host, within a guest. This vulnerability is fixed in 36.0.7, 42.0.2, and 43.0.1.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 9, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-34944 · Other software · bytecodealliance · reported by GitHubMedium 4.1
Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, On x86-64 platforms with SSE3 disabled Wasmtime's compilation of the f64x2.splat WebAssembly instruction with Cranelift may load 8 more bytes than is necessary. When signals-based-traps are disabled this can result in a uncaught segfault due to loading from unmapped guard pages. With guard pages disabled it's possible for out-of-sandbox data to be loaded, but this data is not visible to WebAssembly guests. This vulnerability is fixed in 24.0.7, 36.0.7, 42.0.2, and 43.0.1.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 9, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-34943 · Other software · bytecodealliance · reported by GitHubMedium 5.6
Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a possible panic which can happen when a flags-typed component model value is lifted with the Val type. If bits are set outside of the set of flags the component model specifies that these bits should be ignored but Wasmtime will panic when this value is lifted. This panic only affects wasmtime's implementation of lifting into Val, not when using the flags! macro. This additionally only affects flags-typed values which are part of a WIT interface. This has the risk of being a guest-controlled panic within the host which Wasmtime considers a DoS vector. This vulnerability is fixed in 24.0.7, 36.0.7, 42.0.2, and 43.0.1.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 9, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-34942 · Other software · bytecodealliance · reported by GitHubMedium 5.9
Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime's implementation of transcoding strings into the Component Model's utf16 or latin1+utf16 encodings improperly verified the alignment of reallocated strings. This meant that unaligned pointers could be passed to the host for transcoding which would trigger a host panic. This panic is possible to trigger from malicious guests which transfer very specific strings across components with specific addresses. Host panics are considered a DoS vector in Wasmtime as the panic conditions are controlled by the guest in this situation. This vulnerability is fixed in 24.0.7, 36.0.7, 42.0.2, and 43.0.1.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 9, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-34941 · Other software · bytecodealliance · reported by GitHubMedium 6.9
Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a vulnerability where when transcoding a UTF-16 string to the latin1+utf16 component-model encoding it would incorrectly validate the byte length of the input string when performing a bounds check. Specifically the number of code units were checked instead of the byte length, which is twice the size of the code units. This vulnerability can cause the host to read beyond the end of a WebAssembly's linear memory in an attempt to transcode nonexistent bytes. In Wasmtime's default configuration this will read unmapped memory on a guard page, terminating the process with a segfault. Wasmtime can be configured, however, without guard pages which would mean that host memory beyond the end of linear memory may be read and interpreted as UTF-16. A host segfault is a denial-of-service vulnerability in Wasmtime, and possibly being able to read beyond the end of linear memory is additionally a vulnerability. Note that reading beyond the end of linear memory requires nonstandard configuration of Wasmtime, specifically with guard pages disabled. This vulnerability is fixed in 24.0.7, 36.0.7, 42.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Feb 24, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-27572 · Other software · bytecodealliance · reported by GitHubMedium 6.9
Wasmtime is a runtime for WebAssembly. Prior to versions 24.0.6, 36.0.6, 4.0.04, 41.0.4, and 42.0.0, Wasmtime's implementation of the `wasi:http/types.fields` resource is susceptible to panics when too many fields are added to the set of headers. Wasmtime's implementation in the `wasmtime-wasi-http` crate is backed by a data structure which panics when it reaches excessive capacity and this condition was not handled gracefully in Wasmtime. Panicking in a WASI implementation is a Denial of Service vector for embedders and is treated as a security vulnerability in Wasmtime. Wasmtime 24.0.6, 36.0.6, 40.0.4, 41.0.4, and 42.0.0 patch this vulnerability and return a trap to the guest instead of panicking. There are no known workarounds at this time. Embedders are encouraged to update to a patched version of Wasmtime.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Feb 24, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-27204 · Other software · bytecodealliance · reported by GitHubMedium 6.9
Wasmtime is a runtime for WebAssembly. Prior to versions 24.0.6, 36.0.6, 4.0.04, 41.0.4, and 42.0.0, Wasmtime's implementation of WASI host interfaces are susceptible to guest-controlled resource exhaustion on the host. Wasmtime did not appropriately place limits on resource allocations requested by the guests. This serves as a Denial of Service vector. Wasmtime 24.0.6, 36.0.6, 40.0.4, 41.0.4, and 42.0.0 have all been released with the fix for this issue. These versions do not prevent this issue in their default configuration to avoid breaking preexisting behaviors. All versions of Wasmtime have appropriate knobs to prevent this behavior, and Wasmtime 42.0.0-and-later will have these knobs tuned by default to prevent this issue from happening. There are no known workarounds for this issue without upgrading. Embedders are recommended to upgrade and configure their embeddings as necessary to prevent possibly-malicious guests from triggering this issue.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Feb 24, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-27195 · Other software · bytecodealliance · reported by GitHubMedium 6.9
Wasmtime is a runtime for WebAssembly. Starting with Wasmtime 39.0.0, the `component-model-async` feature became the default, which brought with it a new implementation of `[Typed]Func::call_async` which made it capable of calling async-typed guest export functions. However, that implementation had a bug leading to a panic under certain circumstances: First, the host embedding calls `[Typed]Func::call_async` on a function exported by a component, polling the returned `Future` once. Second, the component function yields control to the async runtime (e.g. Tokio), e.g. due to a call to host function registered using `LinkerInstance::func_wrap_async` which yields, or due an epoch interruption. Third, the host embedding drops the `Future` after polling it once. This leaves the component instance in a non-reenterable state since the call never had a chance to complete. Fourth, the host embedding calls `[Typed]Func::call_async` again, polling the returned `Future`. Since the component instance cannot be entered at this point, the call traps, but not before allocating a task and thread for the call. Fifth, the host embedding ignores the trap and drops the `Future`. This panics due to t
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordbytecodealliance.zulipchat.comgithub.com
Feb 10, 2026A vulnerability has been found in wasm3 up to 0.5.0.CVE-2025-15572 · Other software · Wasm3 Project · reported by VulDBLow 1.9
A vulnerability has been found in wasm3 up to 0.5.0. The affected element is the function NewCodePage. The manipulation leads to memory leak. The attack must be carried out locally. The exploit has been disclosed to the public and may be used. Unfortunately, the project has no active maintainer at the moment.
- Product
- Wasm3
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Jan 27, 2026Wasmtime is a runtime for WebAssembly.CVE-2026-24116 · Other software · bytecodealliance · reported by GitHubMedium 4.1
Wasmtime is a runtime for WebAssembly. Starting in version 29.0.0 and prior to version 36.0.5, 40.0.3, and 41.0.1, on x86-64 platforms with AVX, Wasmtime's compilation of the `f64.copysign` WebAssembly instruction with Cranelift may load 8 more bytes than is necessary. When signals-based-traps are disabled this can result in a uncaught segfault due to loading from unmapped guard pages. With guard pages disabled it's possible for out-of-sandbox data to be loaded, but unless there is another bug in Cranelift this data is not visible to WebAssembly guests. Wasmtime 36.0.5, 40.0.3, and 41.0.1 have been released to fix this issue. Users are recommended to upgrade to the patched versions of Wasmtime. Other affected versions are not patched and users should updated to supported major version instead. This bug can be worked around by enabling signals-based-traps. While disabling guard pages can be a quick fix in some situations, it's not recommended to disabled guard pages as it is a key defense-in-depth measure of Wasmtime.
- Product
- wasmtime
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Jan 1, 2026A vulnerability was detected in wasm3 up to 0.5.0.CVE-2025-15413 · Other software · Wasm3 Project · reported by VulDBLow 1.9
A vulnerability was detected in wasm3 up to 0.5.0. Impacted is the function op_SetSlot_i32/op_CallIndirect of the file m3_exec.h. Performing a manipulation results in memory corruption. The attack needs to be approached locally. The exploit is now public and may be used. Unfortunately, the project has no active maintainer at the moment.
- Product
- Wasm3
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Dec 30, 2025WasmEdge is a WebAssembly runtime.CVE-2025-69261 · Other software · WasmEdge · reported by GitHubMedium 5.5
WasmEdge is a WebAssembly runtime. Prior to version 0.16.0-alpha.3, a multiplication in `WasmEdge/include/runtime/instance/memory.h` can wrap, causing `checkAccessBound()` to incorrectly allow the access. This leads to a segmentation fault. Version 0.16.0-alpha.3 contains a patch for the issue.
- Product
- WasmEdge
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Where this comes from: the exploited list is CISA’s Known Exploited Vulnerabilities catalog. Everything else is the whole National Vulnerability Database, where each record is published by the team that found the bug (Wordfence, Patchstack, WPScan, the vendors themselves and others); we show who. Exploit odds are FIRST’s EPSS, updated daily. Titles and categories are ours, so check the linked record before acting on a detail. For a write-up of the big ones, see our advisories. Every vendor, and every WordPress plugin and theme with a recorded flaw, also has its own page. All of it is free to reuse as JSON, CSV or RSS.
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