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.
29 results
Jun 25, 2026An attacker can send a crafted EDNS OPT record that will be ignored by DNSdist’s filtering rules, but will be rewritten as a valid OPT record when EDNS Client SCVE-2026-42004 · Other software · PowerDNS · reported by security@open-xchange.comLow 3.7
An attacker can send a crafted EDNS OPT record that will be ignored by DNSdist’s filtering rules, but will be rewritten as a valid OPT record when EDNS Client Subnet is inserted, causing the backend to see the EDNS option(s) that DNSdist did not filter.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Jun 25, 2026An attacker can send crafted DNS over HTTP/3 queries, triggering an exception that prevents some buffer from being freed right away.CVE-2026-40211 · Other software · PowerDNS · reported by security@open-xchange.comMedium 5.3
An attacker can send crafted DNS over HTTP/3 queries, triggering an exception that prevents some buffer from being freed right away. The buffer will be freed at the end of the QUIC connection, but on some setups it might be possible to open enough concurrent DoH3 streams to trigger an out-of-memory condition, resulting in a denial of service.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Jun 25, 2026An out-of-bounds read might happen when SetMacAddrAction is used, potentially resulting in uninitialized memory being sent over the network or a crash.CVE-2026-40210 · Other software · PowerDNS · reported by security@open-xchange.comMedium 4.8
An out-of-bounds read might happen when SetMacAddrAction is used, potentially resulting in uninitialized memory being sent over the network or a crash.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Jun 25, 2026An attacker might be able to cause outgoing TCP connections to backend to be stuck until a timeout occurs instead of being released immediately, by sending IXFRCVE-2026-40209 · Other software · PowerDNS · reported by security@open-xchange.comMedium 5.3
An attacker might be able to cause outgoing TCP connections to backend to be stuck until a timeout occurs instead of being released immediately, by sending IXFR queries. This could be used to cause a denial of service if there is a limit to the number of concurrent connections to this backend, or if the process runs out of file descriptors.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Jun 25, 2026An attacker might be able to delay the processing of DoH3 queries by sending DoH3 GET queries with an invalid DATA frame.CVE-2026-40208 · Other software · PowerDNS · reported by security@open-xchange.comLow 3.7
An attacker might be able to delay the processing of DoH3 queries by sending DoH3 GET queries with an invalid DATA frame.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Jun 25, 2026An attacker sending a large number of crafted DNS queries might be able to trigger a dynamic block being inserted with a value causing invalid output to be prodCVE-2026-40011 · Other software · PowerDNS · reported by security@open-xchange.comLow 3.7
An attacker sending a large number of crafted DNS queries might be able to trigger a dynamic block being inserted with a value causing invalid output to be produced in the prometheus endpoint. The prometheus endpoint will then be rejected by the scraper until the dynamic block expires.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 22, 2026A rogue backend can send a crafted UDP response with a query ID off by one related to the maximum configured value, triggering an out-of-bounds write leading toCVE-2026-33602 · Other software · PowerDNS · reported by security@open-xchange.comMedium 6.5
A rogue backend can send a crafted UDP response with a query ID off by one related to the maximum configured value, triggering an out-of-bounds write leading to a denial of service.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 22, 2026A rogue backend can send a crafted SVCB response to a Discovery of Designated Resolvers request, when requested via either the autoUpgrade (Lua) option to newSeCVE-2026-33599 · Other software · PowerDNS · reported by security@open-xchange.comLow 3.1
A rogue backend can send a crafted SVCB response to a Discovery of Designated Resolvers request, when requested via either the autoUpgrade (Lua) option to newServer or auto_upgrade (YAML) settings. DDR upgrade is not enabled by default.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 22, 2026A cached crafted response can cause an out-of-bounds read if custom Lua code calls getDomainListByAddress() or getAddressListByDomain() on a packet cache.CVE-2026-33598 · Other software · PowerDNS · reported by security@open-xchange.comMedium 4.8
A cached crafted response can cause an out-of-bounds read if custom Lua code calls getDomainListByAddress() or getAddressListByDomain() on a packet cache.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 22, 2026PRSD detection denial of serviceCVE-2026-33597 · Other software · PowerDNS · reported by security@open-xchange.comLow 3.7
PRSD detection denial of service
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 22, 2026A client might theoretically be able to cause a mismatch between queries sent to a backend and the received responses by sending a flood of perfectly timed querCVE-2026-33596 · Other software · PowerDNS · reported by security@open-xchange.comLow 3.1
A client might theoretically be able to cause a mismatch between queries sent to a backend and the received responses by sending a flood of perfectly timed queries that are routed to a TCP-only or DNS over TLS backend.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 22, 2026A client can trigger excessive memory allocation by generating a lot of errors responses over a single DoQ and DoH3 connection, as some resources were not propeCVE-2026-33595 · Other software · PowerDNS · reported by security@open-xchange.comMedium 5.3
A client can trigger excessive memory allocation by generating a lot of errors responses over a single DoQ and DoH3 connection, as some resources were not properly released until the end of the connection.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 22, 2026A client can trigger excessive memory allocation by generating a lot of queries that are routed to an overloaded DoH backend, causing queries to accumulate intoCVE-2026-33594 · Other software · PowerDNS · reported by security@open-xchange.comMedium 5.3
A client can trigger excessive memory allocation by generating a lot of queries that are routed to an overloaded DoH backend, causing queries to accumulate into a buffer that will not be released until the end of the connection.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 22, 2026A client can trigger a divide by zero error leading to crash by sending a crafted DNSCrypt query.CVE-2026-33593 · Other software · PowerDNS · reported by security@open-xchange.comHigh 7.5
A client can trigger a divide by zero error leading to crash by sending a crafted DNSCrypt query.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 22, 2026An attacker can create a large number of concurrent DoQ or DoH3 connections, causing unlimited memory allocation in DNSdist and leading to a denial of service.CVE-2026-33254 · Other software · PowerDNS · reported by security@open-xchange.comMedium 5.3
An attacker can create a large number of concurrent DoQ or DoH3 connections, causing unlimited memory allocation in DNSdist and leading to a denial of service. DOQ and DoH3 are disabled by default.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 31, 2026An attacker might be able to trigger a use-after-free by sending crafted DNS queries to a DNSdist using the DNSQuestion:getEDNSOptions method in custom Lua codeCVE-2026-27854 · Other software · PowerDNS · reported by security@open-xchange.comMedium 4.8
An attacker might be able to trigger a use-after-free by sending crafted DNS queries to a DNSdist using the DNSQuestion:getEDNSOptions method in custom Lua code. In some cases DNSQuestion:getEDNSOptions might refer to a version of the DNS packet that has been modified, thus triggering a use-after-free and potentially a crash resulting in denial of service.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 31, 2026An attacker might be able to trigger an out-of-bounds write by sending crafted DNS responses to a DNSdist using the DNSQuestion:changeName or DNSResponse:changeCVE-2026-27853 · Other software · PowerDNS · reported by security@open-xchange.comMedium 5.9
An attacker might be able to trigger an out-of-bounds write by sending crafted DNS responses to a DNSdist using the DNSQuestion:changeName or DNSResponse:changeName methods in custom Lua code. In some cases the rewritten packet might become larger than the initial response and even exceed 65535 bytes, potentially leading to a crash resulting in denial of service.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 31, 2026An attacker might be able to trick DNSdist into allocating too much memory while processing DNS over QUIC or DNS over HTTP/3 payloads, resulting in a denial of CVE-2026-24030 · Other software · PowerDNS · reported by security@open-xchange.comMedium 5.3
An attacker might be able to trick DNSdist into allocating too much memory while processing DNS over QUIC or DNS over HTTP/3 payloads, resulting in a denial of service. In setups with a large quantity of memory available this usually results in an exception and the QUIC connection is properly closed, but in some cases the system might enter an out-of-memory state instead and terminate the process.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 31, 2026When the early_acl_drop (earlyACLDrop in Lua) option is disabled (default is enabled) on a DNS over HTTPs frontend using the nghttp2 provider, the ACL check is CVE-2026-24029 · Other software · PowerDNS · reported by security@open-xchange.comMedium 6.5
When the early_acl_drop (earlyACLDrop in Lua) option is disabled (default is enabled) on a DNS over HTTPs frontend using the nghttp2 provider, the ACL check is skipped, allowing all clients to send DoH queries regardless of the configured ACL.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 31, 2026An attacker might be able to trigger an out-of-bounds read by sending a crafted DNS response packet, when custom Lua code uses newDNSPacketOverlay to parse DNS CVE-2026-24028 · Other software · PowerDNS · reported by security@open-xchange.comMedium 5.3
An attacker might be able to trigger an out-of-bounds read by sending a crafted DNS response packet, when custom Lua code uses newDNSPacketOverlay to parse DNS packets. The out-of-bounds read might trigger a crash, leading to a denial of service, or access unrelated memory, leading to potential information disclosure.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 31, 2026When the internal webserver is enabled (default is disabled), an attacker might be able to trick an administrator logged to the dashboard into visiting a maliciCVE-2026-0397 · Other software · PowerDNS · reported by security@open-xchange.comLow 3.1
When the internal webserver is enabled (default is disabled), an attacker might be able to trick an administrator logged to the dashboard into visiting a malicious website and extract information about the running configuration from the dashboard. The root cause of the issue is a misconfiguration of the Cross-Origin Resource Sharing (CORS) policy.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 31, 2026An attacker might be able to inject HTML content into the internal web dashboard by sending crafted DNS queries to a DNSdist instance where domain-based dynamicCVE-2026-0396 · Other software · PowerDNS · reported by security@open-xchange.comLow 3.1
An attacker might be able to inject HTML content into the internal web dashboard by sending crafted DNS queries to a DNSdist instance where domain-based dynamic rules have been enabled via either DynBlockRulesGroup:setSuffixMatchRule or DynBlockRulesGroup:setSuffixMatchRuleFFI.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 18, 2025In some circumstances, when DNSdist is configured to use the nghttp2 library to process incoming DNS over HTTPS queries, an attacker might be able to cause a deCVE-2025-30187 · Other software · PowerDNS · reported by security@open-xchange.comLow 3.7
In some circumstances, when DNSdist is configured to use the nghttp2 library to process incoming DNS over HTTPS queries, an attacker might be able to cause a denial of service by crafting a DoH exchange that triggers an unbounded I/O read loop, causing an unexpected consumption of CPU resources.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recorddnsdist.orgopenwall.com
May 20, 2025In some circumstances, when DNSdist is configured to allow an unlimited number of queries on a single, incoming TCP connection from a client, an attacker can caCVE-2025-30193 · Other software · PowerDNS · reported by security@open-xchange.comHigh 7.5
In some circumstances, when DNSdist is configured to allow an unlimited number of queries on a single, incoming TCP connection from a client, an attacker can cause a denial of service by crafting a TCP exchange that triggers an exhaustion of the stack and a crash of DNSdist, causing a denial of service. The remedy is: upgrade to the patched 1.9.10 version. A workaround is to restrict the maximum number of queries on incoming TCP connections to a safe value, like 50, via the setMaxTCPQueriesPerConnection setting. We would like to thank Renaud Allard for bringing this issue to our attention.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 29, 2025When DNSdist is configured to provide DoH via the nghttp2 provider, an attacker can cause a denial of service by crafting a DoH exchange that triggers an illegaCVE-2025-30194 · Other software · PowerDNS · reported by security@open-xchange.comHigh 7.5
When DNSdist is configured to provide DoH via the nghttp2 provider, an attacker can cause a denial of service by crafting a DoH exchange that triggers an illegal memory access (double-free) and crash of DNSdist, causing a denial of service. The remedy is: upgrade to the patched 1.9.9 version. A workaround is to temporarily switch to the h2o provider until DNSdist has been upgraded to a fixed version. We would like to thank Charles Howes for bringing this issue to our attention.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recorddnsdist.orgopenwall.com
May 14, 2024When incoming DNS over HTTPS support is enabled using the nghttp2 provider, and queries are routed to a tcp-only or DNS over TLS backend, an attacker can triggeCVE-2024-25581 · Other software · PowerDNS · reported by security@open-xchange.comHigh 7.5
When incoming DNS over HTTPS support is enabled using the nghttp2 provider, and queries are routed to a tcp-only or DNS over TLS backend, an attacker can trigger an assertion failure in DNSdist by sending a request for a zone transfer (AXFR or IXFR) over DNS over HTTPS, causing the process to stop and thus leading to a Denial of Service. DNS over HTTPS is not enabled by default, and backends are using plain DNS (Do53) by default.
- Product
- DNSdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordopenwall.comdnsdist.org
Nov 26, 2018An issue has been found in PowerDNS DNSDist before 1.3.3 allowing a remote attacker to craft a DNS query with trailing data such that the addition of a record bCVE-2018-14663 · Other software · [UNKNOWN] · reported by Red HatMedium 5.9
An issue has been found in PowerDNS DNSDist before 1.3.3 allowing a remote attacker to craft a DNS query with trailing data such that the addition of a record by dnsdist, for example an OPT record when adding EDNS Client Subnet, might result in the trailing data being smuggled to the backend as a valid record while not seen by dnsdist. This is an issue when dnsdist is deployed as a DNS Firewall and used to filter some records that should not be received by the backend. This issue occurs only when either the 'useClientSubnet' or the experimental 'addXPF' parameters are used when declaring a new backend.
- Product
- dnsdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordbugzilla.redhat.comdnsdist.org
Sep 11, 2018An issue has been found in dnsdist before 1.2.0 in the way EDNS0 OPT records are handled when parsing responses from a backend.CVE-2016-7069 · Other software · Open-Xchange · reported by Red HatMedium 5.9
An issue has been found in dnsdist before 1.2.0 in the way EDNS0 OPT records are handled when parsing responses from a backend. When dnsdist is configured to add EDNS Client Subnet to a query, the response may contain an EDNS0 OPT record that has to be removed before forwarding the response to the initial client. On a 32-bit system, the pointer arithmetic used when parsing the received response to remove that record might trigger an undefined behavior leading to a crash.
- Product
- dnsdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordsecurityfocus.combugzilla.redhat.com
Aug 22, 2017dnsdist version 1.1.0 is vulnerable to a flaw in authentication mechanism for REST API potentially allowing CSRF attack.CVE-2017-7557 · Other software · Red Hat, Inc. · reported by Red HatHigh 8.8
dnsdist version 1.1.0 is vulnerable to a flaw in authentication mechanism for REST API potentially allowing CSRF attack.
- Product
- dnsdist
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordsecurityfocus.comdnsdist.org
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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