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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.

1,764exploited flaws on CISA’s list

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78 results · page 2 of 2

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.
Full record and what to do →NVD record docs.rs github.com
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.
Full record and what to do →NVD record docs.rs docs.rs
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 record bytecodealliance.zulipchat.com github.com
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.
Full record and what to do →NVD record docs.rs docs.rs
Nov 12, 2025Wasmtime is a runtime for WebAssembly.CVE-2025-64345 · Other software · bytecodealliance · reported by GitHubLow 1.8
Wasmtime is a runtime for WebAssembly. Prior to version 38.0.4, 37.0.3, 36.0.3, and 24.0.5, Wasmtime's Rust embedder API contains an unsound interaction where a WebAssembly shared linear memory could be viewed as a type which provides safe access to the host (Rust) to the contents of the linear memory. This is not sound for shared linear memories, which could be modified in parallel, and this could lead to a data race in the host. Patch releases have been issued for all supported versions of Wasmtime, notably: 24.0.5, 36.0.3, 37.0.3, and 38.0.4. These releases reject creation of shared memories via `Memory::new` and shared memories are now excluded from core dumps. As a workaround, eembeddings affected by this issue should use `SharedMemory::new` instead of `Memory::new` to create shared memories. Affected embeddings should also disable core dumps if they are unable to upgrade. Note that core dumps are disabled by default but the wasm threads proposal (and shared memory) is enabled by default.
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record docs.rs docs.rs
Oct 24, 2025Wasmtime is a runtime for WebAssembly.CVE-2025-62711 · Other software · bytecodealliance · reported by GitHubLow 2.1
Wasmtime is a runtime for WebAssembly. In versions from 38.0.0 to before 38.0.3, the implementation of component-model related host-to-wasm trampolines in Wasmtime contained a bug where it's possible to carefully craft a component, which when called in a specific way, would crash the host with a segfault or assert failure. Wasmtime 38.0.3 has been released and is patched to fix this issue. There are no workarounds.
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com github.com
Oct 7, 2025Wasmtime is a runtime for WebAssembly.CVE-2025-61670 · Other software · bytecodealliance · reported by GitHubLow 1
Wasmtime is a runtime for WebAssembly. Wasmtime 37.0.0 and 37.0.1 have memory leaks in the C/C++ API when using bindings for the `anyref` or `externref` WebAssembly values. This is caused by a regression introduced during the development of 37.0.0 and all prior versions of Wasmtime are unaffected. If `anyref` or `externref` is not used in the C/C++ API then embeddings are also unaffected by the leaky behavior. The `wasmtime` Rust crate is unaffected by this leak. Development of Wasmtime 37.0.0 included a refactoring in Rust of changing the old `ManuallyRooted<T>` type to a new `OwnedRooted<T>` type. This change was integrated into Wasmtime's C API but left the C API in a state which had memory leaks. Additionally the new ownership semantics around this type were not reflected into the C++ API, making it leak-prone. A short version of the change is that previously `ManuallyRooted<T>`, as the name implies, required manual calls to an "unroot" operation. If this was forgotten then the memory was still cleaned up when the `wasmtime_store_t` itself was destroyed eventually. Documentation of when to "unroot" was sparse and there were already situations prior to 37.0.0 where memory would
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com github.com
Jul 18, 2025Wasmtime is a runtime for WebAssembly.CVE-2025-53901 · Other software · bytecodealliance · reported by GitHubLow 3.5
Wasmtime is a runtime for WebAssembly. Prior to versions 24.0.4, 33.0.2, and 34.0.2, a bug in Wasmtime's implementation of the WASIp1 set of import functions can lead to a WebAssembly guest inducing a panic in the host (embedder). The specific bug is triggered by calling `path_open` after calling `fd_renumber` with either two equal argument values or a second argument being equal to a previously-closed file descriptor number value. The corrupt state introduced in `fd_renumber` will lead to the subsequent opening of a file descriptor to panic. This panic cannot introduce memory unsafety or allow WebAssembly to break outside of its sandbox, however. There is no possible heap corruption or memory unsafety from this panic. This bug is in the implementation of Wasmtime's `wasmtime-wasi` crate which provides an implementation of WASIp1. The bug requires a specially crafted call to `fd_renumber` in addition to the ability to open a subsequent file descriptor. Opening a second file descriptor is only possible when a preopened directory was provided to the guest, and this is common amongst embeddings. A panic in the host is considered a denial-of-service vector for WebAssembly embedders and
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record docs.wasmtime.dev docs.wasmtime.dev
Nov 5, 2024Wasmtime is a fast and secure runtime for WebAssembly.CVE-2024-51745 · Other software · bytecodealliance · reported by GitHubLow 2.3
Wasmtime is a fast and secure runtime for WebAssembly. Wasmtime's filesystem sandbox implementation on Windows blocks access to special device filenames such as "COM1", "COM2", "LPT0", "LPT1", and so on, however it did not block access to the special device filenames which use superscript digits, such as "COM¹", "COM²", "LPT⁰", "LPT¹", and so on. Untrusted Wasm programs that are given access to any filesystem directory could bypass the sandbox and access devices through those special device filenames with superscript digits, and through them gain access peripheral devices connected to the computer, or network resources mapped to those devices. This can include modems, printers, network printers, and any other device connected to a serial or parallel port, including emulated USB serial ports. Patch releases for Wasmtime have been issued as 24.0.2, 25.0.3, and 26.0.1. Users of Wasmtime 23.0.x and prior are recommended to upgrade to one of these patched versions. There are no known workarounds for this issue. Affected Windows users are recommended to upgrade.
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record en.wikipedia.org github.com
Oct 9, 2024Wasmtime is an open source runtime for WebAssembly.CVE-2024-47813 · Other software · bytecodealliance · reported by GitHubLow 2.9
Wasmtime is an open source runtime for WebAssembly. Under certain concurrent event orderings, a `wasmtime::Engine`'s internal type registry was susceptible to double-unregistration bugs due to a race condition, leading to panics and potentially type registry corruption. That registry corruption could, following an additional and particular sequence of concurrent events, lead to violations of WebAssembly's control-flow integrity (CFI) and type safety. Users that do not use `wasmtime::Engine` across multiple threads are not affected. Users that only create new modules across threads over time are additionally not affected. Reproducing this bug requires creating and dropping multiple type instances (such as `wasmtime::FuncType` or `wasmtime::ArrayType`) concurrently on multiple threads, where all types are associated with the same `wasmtime::Engine`. **Wasm guests cannot trigger this bug.** See the "References" section below for a list of Wasmtime types-related APIs that are affected. Wasmtime maintains an internal registry of types within a `wasmtime::Engine` and an engine is shareable across threads. Types can be created and referenced through creation of a `wasmtime::Module`, creat
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com github.com
Oct 9, 2024Wasmtime is an open source runtime for WebAssembly.CVE-2024-47763 · Other software · bytecodealliance · reported by GitHubMedium 5.5
Wasmtime is an open source runtime for WebAssembly. Wasmtime's implementation of WebAssembly tail calls combined with stack traces can result in a runtime crash in certain WebAssembly modules. The runtime crash may be undefined behavior if Wasmtime was compiled with Rust 1.80 or prior. The runtime crash is a deterministic process abort when Wasmtime is compiled with Rust 1.81 and later. WebAssembly tail calls are a proposal which relatively recently reached stage 4 in the standardization process. Wasmtime first enabled support for tail calls by default in Wasmtime 21.0.0, although that release contained a bug where it was only on-by-default for some configurations. In Wasmtime 22.0.0 tail calls were enabled by default for all configurations. The specific crash happens when an exported function in a WebAssembly module (or component) performs a `return_call` (or `return_call_indirect` or `return_call_ref`) to an imported host function which captures a stack trace (for example, the host function raises a trap). In this situation, the stack-walking code previously assumed there was always at least one WebAssembly frame on the stack but with tail calls that is no longer true. With the 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 record docs.rs github.com
Apr 4, 2024wasmtime is a runtime for WebAssembly.CVE-2024-30266 · Other software · bytecodealliance · reported by GitHubLow 3.3
wasmtime is a runtime for WebAssembly. The 19.0.0 release of Wasmtime contains a regression introduced during its development which can lead to a guest WebAssembly module causing a panic in the host runtime. A valid WebAssembly module, when executed at runtime, may cause this panic. This vulnerability has been patched in version 19.0.1.
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com github.com
Sep 15, 2023Wasmtime is a standalone runtime for WebAssembly.CVE-2023-41880 · Other software · bytecodealliance · reported by GitHubLow 2.2
Wasmtime is a standalone runtime for WebAssembly. Wasmtime versions from 10.0.0 to versions 10.02, 11.0.2, and 12.0.1 contain a miscompilation of the WebAssembly `i64x2.shr_s` instruction on x86_64 platforms when the shift amount is a constant value that is larger than 32. Only x86_64 is affected so all other targets are not affected by this. The miscompilation results in the instruction producing an incorrect result, namely the low 32-bits of the second lane of the vector are derived from the low 32-bits of the second lane of the input vector instead of the high 32-bits. The primary impact of this issue is that any WebAssembly program using the `i64x2.shr_s` with a constant shift amount larger than 32 may produce an incorrect result. This issue is not an escape from the WebAssembly sandbox. Execution of WebAssembly guest programs will still behave correctly with respect to memory sandboxing and isolation from the host. Wasmtime considers non-spec-compliant behavior as a security issue nonetheless. This issue was discovered through fuzzing of Wasmtime's code generator Cranelift. Wasmtime versions 10.0.2, 11.0.2, and 12.0.2 are all patched to no longer have this miscompilation. 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 record docs.rs github.com
Apr 27, 2023Wasmtime is a standalone runtime for WebAssembly.CVE-2023-30624 · Other software · bytecodealliance · reported by GitHubLow 3.9
Wasmtime is a standalone runtime for WebAssembly. Prior to versions 6.0.2, 7.0.1, and 8.0.1, Wasmtime's implementation of managing per-instance state, such as tables and memories, contains LLVM-level undefined behavior. This undefined behavior was found to cause runtime-level issues when compiled with LLVM 16 which causes some writes, which are critical for correctness, to be optimized away. Vulnerable versions of Wasmtime compiled with Rust 1.70, which is currently in beta, or later are known to have incorrectly compiled functions. Versions of Wasmtime compiled with the current Rust stable release, 1.69, and prior are not known at this time to have any issues, but can theoretically exhibit potential issues. The underlying problem is that Wasmtime's runtime state for an instance involves a Rust-defined structure called `Instance` which has a trailing `VMContext` structure after it. This `VMContext` structure has a runtime-defined layout that is unique per-module. This representation cannot be expressed with safe code in Rust so `unsafe` code is required to maintain this state. The code doing this, however, has methods which take `&self` as an argument but modify data in the `VMCon
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com github.com
Mar 8, 2023wasmtime is a fast and secure runtime for WebAssembly.CVE-2023-27477 · Other software · bytecodealliance · reported by GitHubLow 3.1
wasmtime is a fast and secure runtime for WebAssembly. Wasmtime's code generation backend, Cranelift, has a bug on x86_64 platforms for the WebAssembly `i8x16.select` instruction which will produce the wrong results when the same operand is provided to the instruction and some of the selected indices are greater than 16. There is an off-by-one error in the calculation of the mask to the `pshufb` instruction which causes incorrect results to be returned if lanes are selected from the second vector. This codegen bug has been fixed in Wasmtiem 6.0.1, 5.0.1, and 4.0.1. Users are recommended to upgrade to these updated versions. If upgrading is not an option for you at this time, you can avoid this miscompilation by disabling the Wasm simd proposal. Additionally the bug is only present on x86_64 hosts. Other platforms such as AArch64 and s390x are not affected.
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record docs.rs github.com
Mar 8, 2023wasmtime is a fast and secure runtime for WebAssembly.CVE-2023-26489 · Other software · bytecodealliance · reported by GitHubCritical 9.9
wasmtime is a fast and secure runtime for WebAssembly. In affected versions wasmtime's code generator, Cranelift, has a bug on x86_64 targets where address-mode computation mistakenly would calculate a 35-bit effective address instead of WebAssembly's defined 33-bit effective address. This bug means that, with default codegen settings, a wasm-controlled load/store operation could read/write addresses up to 35 bits away from the base of linear memory. Due to this bug, however, addresses up to `0xffffffff * 8 + 0x7ffffffc = 36507222004 = ~34G` bytes away from the base of linear memory are possible from guest code. This means that the virtual memory 6G away from the base of linear memory up to ~34G away can be read/written by a malicious module. A guest module can, without the knowledge of the embedder, read/write memory in this region. The memory may belong to other WebAssembly instances when using the pooling allocator, for example. Affected embedders are recommended to analyze preexisting wasm modules to see if they're affected by the incorrect codegen rules and possibly correlate that with an anomalous number of traps during historical execution to locate possibly suspicious modul
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record docs.rs docs.rs
Nov 10, 2022Wasmtime is a standalone runtime for WebAssembly.CVE-2022-39394 · Other software · bytecodealliance · reported by GitHubLow 3.8
Wasmtime is a standalone runtime for WebAssembly. Prior to version 2.0.2, there is a bug in Wasmtime's C API implementation where the definition of the `wasmtime_trap_code` does not match its declared signature in the `wasmtime/trap.h` header file. This discrepancy causes the function implementation to perform a 4-byte write into a 1-byte buffer provided by the caller. This can lead to three zero bytes being written beyond the 1-byte location provided by the caller. This bug has been patched and users should upgrade to Wasmtime 2.0.2. This bug can be worked around by providing a 4-byte buffer casted to a 1-byte buffer when calling `wasmtime_trap_code`. Users of the `wasmtime` crate are not affected by this issue, only users of the C API function `wasmtime_trap_code` are affected.
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com github.com
Nov 10, 2022Wasmtime is a standalone runtime for WebAssembly.CVE-2022-39393 · Other software · bytecodealliance · reported by GitHubHigh 8.6
Wasmtime is a standalone runtime for WebAssembly. Prior to versions 2.0.2 and 1.0.2, there is a bug in Wasmtime's implementation of its pooling instance allocator where when a linear memory is reused for another instance the initial heap snapshot of the prior instance can be visible, erroneously to the next instance. This bug has been patched and users should upgrade to Wasmtime 2.0.2 and 1.0.2. Other mitigations include disabling the pooling allocator and disabling the `memory-init-cow`.
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com github.com
Nov 10, 2022Wasmtime is a standalone runtime for WebAssembly.CVE-2022-39392 · Other software · bytecodealliance · reported by GitHubMedium 5.9
Wasmtime is a standalone runtime for WebAssembly. Prior to version 2.0.2, there is a bug in Wasmtime's implementation of its pooling instance allocator when the allocator is configured to give WebAssembly instances a maximum of zero pages of memory. In this configuration, the virtual memory mapping for WebAssembly memories did not meet the compiler-required configuration requirements for safely executing WebAssembly modules. Wasmtime's default settings require virtual memory page faults to indicate that wasm reads/writes are out-of-bounds, but the pooling allocator's configuration would not create an appropriate virtual memory mapping for this meaning out of bounds reads/writes can successfully read/write memory unrelated to the wasm sandbox within range of the base address of the memory mapping created by the pooling allocator. This bug is not applicable with the default settings of the `wasmtime` crate. This bug can only be triggered by setting `InstanceLimits::memory_pages` to zero. This is expected to be a very rare configuration since this means that wasm modules cannot allocate any pages of linear memory. All wasm modules produced by all current toolchains are highly likely 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 record github.com github.com
Jul 22, 2022Wasmtime is a standalone runtime for WebAssembly.CVE-2022-31169 · Other software · bytecodealliance · reported by GitHubMedium 5.9
Wasmtime is a standalone runtime for WebAssembly. There is a bug in Wasmtime's code generator, Cranelift, for AArch64 targets where constant divisors can result in incorrect division results at runtime. This affects Wasmtime prior to version 0.38.2 and Cranelift prior to 0.85.2. This issue only affects the AArch64 platform. Other platforms are not affected. The translation rules for constants did not take into account whether sign or zero-extension should happen which resulted in an incorrect value being placed into a register when a division was encountered. The impact of this bug is that programs executing within the WebAssembly sandbox would not behave according to the WebAssembly specification. This means that it is hypothetically possible for execution within the sandbox to go awry and WebAssembly programs could produce unexpected results. This should not impact hosts executing WebAssembly but does affect the correctness of guest programs. This bug has been patched in Wasmtime version 0.38.2 and cranelift-codegen 0.85.2. There are no known workarounds.
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com github.com
Jul 21, 2022Wasmtime is a standalone runtime for WebAssembly.CVE-2022-31146 · Other software · bytecodealliance · reported by GitHubMedium 6.4
Wasmtime is a standalone runtime for WebAssembly. There is a bug in the Wasmtime's code generator, Cranelift, where functions using reference types may be incorrectly missing metadata required for runtime garbage collection. This means that if a GC happens at runtime then the GC pass will mistakenly think these functions do not have live references to GC'd values, reclaiming them and deallocating them. The function will then subsequently continue to use the values assuming they had not been GC'd, leading later to a use-after-free. This bug was introduced in the migration to the `regalloc2` register allocator that occurred in the Wasmtime 0.37.0 release on 2022-05-20. This bug has been patched and users should upgrade to Wasmtime version 0.38.2. Mitigations for this issue can be achieved by disabling the reference types proposal by passing `false` to `wasmtime::Config::wasm_reference_types` or downgrading to Wasmtime 0.36.0 or prior.
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com github.com
Jun 27, 2022Wasmtime is a standalone runtime for WebAssembly.CVE-2022-31104 · Other software · bytecodealliance · reported by GitHubMedium 4.8
Wasmtime is a standalone runtime for WebAssembly. In affected versions wasmtime's implementation of the SIMD proposal for WebAssembly on x86_64 contained two distinct bugs in the instruction lowerings implemented in Cranelift. The aarch64 implementation of the simd proposal is not affected. The bugs were presented in the `i8x16.swizzle` and `select` WebAssembly instructions. The `select` instruction is only affected when the inputs are of `v128` type. The correspondingly affected Cranelift instructions were `swizzle` and `select`. The `swizzle` instruction lowering in Cranelift erroneously overwrote the mask input register which could corrupt a constant value, for example. This means that future uses of the same constant may see a different value than the constant itself. The `select` instruction lowering in Cranelift wasn't correctly implemented for vector types that are 128-bits wide. When the condition was 0 the wrong instruction was used to move the correct input to the output of the instruction meaning that only the low 32 bits were moved and the upper 96 bits of the result were left as whatever the register previously contained (instead of the input being moved from). The `se
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record docs.rs github.com
Mar 31, 2022Wasmtime is a standalone JIT-style runtime for WebAssembly, using Cranelift.CVE-2022-24791 · Other software · bytecodealliance · reported by GitHubHigh 8.1
Wasmtime is a standalone JIT-style runtime for WebAssembly, using Cranelift. There is a use after free vulnerability in Wasmtime when both running Wasm that uses externrefs and enabling epoch interruption in Wasmtime. If you are not explicitly enabling epoch interruption (it is disabled by default) then you are not affected. If you are explicitly disabling the Wasm reference types proposal (it is enabled by default) then you are also not affected. The use after free is caused by Cranelift failing to emit stack maps when there are safepoints inside cold blocks. Cold blocks occur when epoch interruption is enabled. Cold blocks are emitted at the end of compiled functions, and change the order blocks are emitted versus defined. This reordering accidentally caused Cranelift to skip emitting some stack maps because it expected to emit the stack maps in block definition order, rather than block emission order. When Wasmtime would eventually collect garbage, it would fail to find live references on the stack because of the missing stack maps, think that they were unreferenced garbage, and therefore reclaim them. Then after the collection ended, the Wasm code could use the reclaimed-too-ea
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com github.com
Feb 16, 2022Wasmtime is an open source runtime for WebAssembly & WASI.CVE-2022-23636 · Other software · bytecodealliance · reported by GitHubMedium 5.1
Wasmtime is an open source runtime for WebAssembly & WASI. Prior to versions 0.34.1 and 0.33.1, there exists a bug in the pooling instance allocator in Wasmtime's runtime where a failure to instantiate an instance for a module that defines an `externref` global will result in an invalid drop of a `VMExternRef` via an uninitialized pointer. A number of conditions listed in the GitHub Security Advisory must be true in order for an instance to be vulnerable to this issue. Maintainers believe that the effective impact of this bug is relatively small because the usage of `externref` is still uncommon and without a resource limiter configured on the `Store`, which is not the default configuration, it is only possible to trigger the bug from an error returned by `mprotect` or `VirtualAlloc`. Note that on Linux with the `uffd` feature enabled, it is only possible to trigger the bug from a resource limiter as the call to `mprotect` is skipped. The bug has been fixed in 0.34.1 and 0.33.1 and users are encouraged to upgrade as soon as possible. If it is not possible to upgrade to version 0.34.1 or 0.33.1 of the `wasmtime` crate, it is recommend that support for the reference types proposal be
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com github.com
Sep 17, 2021Wasmtime is an open source runtime for WebAssembly & WASI.CVE-2021-39218 · Other software · bytecodealliance · reported by GitHubMedium 6.3
Wasmtime is an open source runtime for WebAssembly & WASI. In Wasmtime from version 0.26.0 and before version 0.30.0 is affected by a memory unsoundness vulnerability. There was an invalid free and out-of-bounds read and write bug when running Wasm that uses `externref`s in Wasmtime. To trigger this bug, Wasmtime needs to be running Wasm that uses `externref`s, the host creates non-null `externrefs`, Wasmtime performs a garbage collection (GC), and there has to be a Wasm frame on the stack that is at a GC safepoint where there are no live references at this safepoint, and there is a safepoint with live references earlier in this frame's function. Under this scenario, Wasmtime would incorrectly use the GC stack map for the safepoint from earlier in the function instead of the empty safepoint. This would result in Wasmtime treating arbitrary stack slots as `externref`s that needed to be rooted for GC. At the *next* GC, it would be determined that nothing was referencing these bogus `externref`s (because nothing could ever reference them, because they are not really `externref`s) and then Wasmtime would deallocate them and run `<ExternRef as Drop>::drop` on them. This results in a fre
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record crates.io github.com
Sep 17, 2021Wasmtime is an open source runtime for WebAssembly & WASI.CVE-2021-39219 · Other software · bytecodealliance · reported by GitHubMedium 6.3
Wasmtime is an open source runtime for WebAssembly & WASI. Wasmtime before version 0.30.0 is affected by a type confusion vulnerability. As a Rust library the `wasmtime` crate clearly marks which functions are safe and which are `unsafe`, guaranteeing that if consumers never use `unsafe` then it should not be possible to have memory unsafety issues in their embeddings of Wasmtime. An issue was discovered in the safe API of `Linker::func_*` APIs. These APIs were previously not sound when one `Engine` was used to create the `Linker` and then a different `Engine` was used to create a `Store` and then the `Linker` was used to instantiate a module into that `Store`. Cross-`Engine` usage of functions is not supported in Wasmtime and this can result in type confusion of function pointers, resulting in being able to safely call a function with the wrong type. Triggering this bug requires using at least two `Engine` values in an embedding and then additionally using two different values with a `Linker` (one at the creation time of the `Linker` and another when instantiating a module with the `Linker`). It's expected that usage of more-than-one `Engine` in an embedding is relatively rare sin
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record crates.io github.com
Sep 17, 2021Wasmtime is an open source runtime for WebAssembly & WASI.CVE-2021-39216 · Other software · bytecodealliance · reported by GitHubMedium 6.3
Wasmtime is an open source runtime for WebAssembly & WASI. In Wasmtime from version 0.19.0 and before version 0.30.0 there was a use-after-free bug when passing `externref`s from the host to guest Wasm content. To trigger the bug, you have to explicitly pass multiple `externref`s from the host to a Wasm instance at the same time, either by passing multiple `externref`s as arguments from host code to a Wasm function, or returning multiple `externref`s to Wasm from a multi-value return function defined in the host. If you do not have host code that matches one of these shapes, then you are not impacted. If Wasmtime's `VMExternRefActivationsTable` became filled to capacity after passing the first `externref` in, then passing in the second `externref` could trigger a garbage collection. However the first `externref` is not rooted until we pass control to Wasm, and therefore could be reclaimed by the collector if nothing else was holding a reference to it or otherwise keeping it alive. Then, when control was passed to Wasm after the garbage collection, Wasm could use the first `externref`, which at this point has already been freed. We have reason to believe that the effective impact of
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record crates.io github.com
May 24, 2021Cranelift is an open-source code generator maintained by Bytecode Alliance.CVE-2021-32629 · Other software · bytecodealliance · reported by GitHubHigh 7.2
Cranelift is an open-source code generator maintained by Bytecode Alliance. It translates a target-independent intermediate representation into executable machine code. There is a bug in 0.73 of the Cranelift x64 backend that can create a scenario that could result in a potential sandbox escape in a Wasm program. This bug was introduced in the new backend on 2020-09-08 and first included in a release on 2020-09-30, but the new backend was not the default prior to 0.73. The recently-released version 0.73 with default settings, and prior versions with an explicit build flag to select the new backend, are vulnerable. The bug in question performs a sign-extend instead of a zero-extend on a value loaded from the stack, under a specific set of circumstances. If those circumstances occur, the bug could allow access to memory addresses upto 2GiB before the start of the Wasm program heap. If the heap bound is larger than 2GiB, then it would be possible to read memory from a computable range dependent on the size of the heaps bound. The impact of this bug is highly dependent on heap implementation, specifically: * if the heap has bounds checks, and * does not rely exclusively on guard pages,
Product
wasmtime
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record crates.io github.com

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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