# CVE-2026-12725: Dnsmasq: dnsmasq: heap buffer overflow in log_query() when logging unsupported ds/dnskey replies CVE-2026-12725 is fixed in 4 products on 1 platform, first by dnsmasq 2.92-1ubuntu0.4, released June 23, 2026. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-12725 - Priority: Routine - CVSS: 5.9 (Moderate) - EPSS: 0.0053 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jun 22, 2026 - Weakness: Heap-based Buffer Overflow - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-12725 ## Description A heap-based buffer overflow was found in dnsmasq. When DNSSEC validation and query logging are both enabled, logging of DS or DNSKEY replies containing unsupported algorithm or digest types can cause dnsmasq to write past the end of an internal logging buffer. A remote attacker able to supply such a DNS response may crash the dnsmasq process, resulting in denial of service. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | dnsmasq Debian 13.5 (trixie) | 2.91-1+deb13u2 | [DEBIAN-CVE-2026-12725](https://patchblox.com/security/data/fix/linux/debian-cve-2026-12725.md) | Jun 24, 2026 | | Linux | dnsmasq Debian 14 | 2.93-1 | [DEBIAN-CVE-2026-12725](https://patchblox.com/security/data/fix/linux/debian-cve-2026-12725.md) | Jun 24, 2026 | | Linux | dnsmasq Ubuntu 18.04.6 LTS (bionic) | 2.90-0ubuntu0.18.04.1+esm4 | [dnsmasq 2.90-0ubuntu0.18.04.1+esm4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-dnsmasq-2.90-0ubuntu0.18.04.1-esm4.md) | Jul 18, 2026 | | Linux | dnsmasq Ubuntu 20.04 LTS (focal) | 2.90-0ubuntu0.20.04.1+esm3 | [dnsmasq 2.90-0ubuntu0.20.04.1+esm3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-dnsmasq-2.90-0ubuntu0.20.04.1-esm3.md) | Jul 18, 2026 | | Linux | dnsmasq Ubuntu 22.04.1 LTS (jammy) | 2.90-0ubuntu0.22.04.4 | [dnsmasq 2.90-0ubuntu0.22.04.4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-dnsmasq-2.90-0ubuntu0.22.04.4.md) | Jul 18, 2026 | | Linux | dnsmasq Ubuntu 24.04.5 LTS (noble) | 2.90-2ubuntu0.4 | [dnsmasq 2.90-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-noble-dnsmasq-2.90-2ubuntu0.4.md) | Jul 18, 2026 | | Linux | dnsmasq Ubuntu 26.04.1 LTS (resolute) | 2.92-1ubuntu0.4 | [dnsmasq 2.92-1ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-dnsmasq-2.92-1ubuntu0.4.md) | Jun 23, 2026 | | Linux | dnsmasq opensuse-leap 16.0 | 2.93-160000.1.1 | [OPENSUSE-SU-2026:21192-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21192-1.md) | Jun 29, 2026 | | Linux | dnsmasq sles 15.6 | 2.93-150400.16.17.1 | [SUSE-SU-2026:3028-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3028-1.md) | Jul 15, 2026 | | Linux | dnsmasq sles 15.7 | 2.93-150400.16.17.1 | [SUSE-SU-2026:3028-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3028-1.md) | Jul 15, 2026 | | Linux | dnsmasq sles 16.0 | 2.93-160000.1.1 | [SUSE-SU-2026:22496-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22496-1.md) | Jun 29, 2026 | | Linux | dnsmasq-base Ubuntu 18.04.6 LTS (bionic) | 2.90-0ubuntu0.18.04.1+esm4 | [dnsmasq-base 2.90-0ubuntu0.18.04.1+esm4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-dnsmasq-base-2.90-0ubuntu0.18.04.1-esm4.md) | Jul 18, 2026 | | Linux | dnsmasq-base Ubuntu 20.04 LTS (focal) | 2.90-0ubuntu0.20.04.1+esm3 | [dnsmasq-base 2.90-0ubuntu0.20.04.1+esm3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-dnsmasq-base-2.90-0ubuntu0.20.04.1-esm3.md) | Jul 18, 2026 | | Linux | dnsmasq-base Ubuntu 22.04.1 LTS (jammy) | 2.90-0ubuntu0.22.04.4 | [dnsmasq-base 2.90-0ubuntu0.22.04.4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-dnsmasq-base-2.90-0ubuntu0.22.04.4.md) | Jul 18, 2026 | | Linux | dnsmasq-base Ubuntu 24.04.5 LTS (noble) | 2.90-2ubuntu0.4 | [dnsmasq-base 2.90-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-noble-dnsmasq-base-2.90-2ubuntu0.4.md) | Jul 18, 2026 | | Linux | dnsmasq-base Ubuntu 26.04.1 LTS (resolute) | 2.92-1ubuntu0.4 | [dnsmasq-base 2.92-1ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-dnsmasq-base-2.92-1ubuntu0.4.md) | Jun 23, 2026 | | Linux | dnsmasq-base-lua Ubuntu 18.04.6 LTS (bionic) | 2.90-0ubuntu0.18.04.1+esm4 | [dnsmasq-base-lua 2.90-0ubuntu0.18.04.1+esm4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-dnsmasq-base-lua-2.90-0ubuntu0.18.04.1-esm4.md) | Jul 18, 2026 | | Linux | dnsmasq-base-lua Ubuntu 20.04 LTS (focal) | 2.90-0ubuntu0.20.04.1+esm3 | [dnsmasq-base-lua 2.90-0ubuntu0.20.04.1+esm3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-dnsmasq-base-lua-2.90-0ubuntu0.20.04.1-esm3.md) | Jul 18, 2026 | | Linux | dnsmasq-base-lua Ubuntu 22.04.1 LTS (jammy) | 2.90-0ubuntu0.22.04.4 | [dnsmasq-base-lua 2.90-0ubuntu0.22.04.4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-dnsmasq-base-lua-2.90-0ubuntu0.22.04.4.md) | Jul 18, 2026 | | Linux | dnsmasq-base-lua Ubuntu 24.04.5 LTS (noble) | 2.90-2ubuntu0.4 | [dnsmasq-base-lua 2.90-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-noble-dnsmasq-base-lua-2.90-2ubuntu0.4.md) | Jul 18, 2026 | | Linux | dnsmasq-base-lua Ubuntu 26.04.1 LTS (resolute) | 2.92-1ubuntu0.4 | [dnsmasq-base-lua 2.92-1ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-dnsmasq-base-lua-2.92-1ubuntu0.4.md) | Jun 23, 2026 | | Linux | dnsmasq-utils Ubuntu 18.04.6 LTS (bionic) | 2.90-0ubuntu0.18.04.1+esm4 | [dnsmasq-utils 2.90-0ubuntu0.18.04.1+esm4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-dnsmasq-utils-2.90-0ubuntu0.18.04.1-esm4.md) | Jul 18, 2026 | | Linux | dnsmasq-utils Ubuntu 20.04 LTS (focal) | 2.90-0ubuntu0.20.04.1+esm3 | [dnsmasq-utils 2.90-0ubuntu0.20.04.1+esm3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-dnsmasq-utils-2.90-0ubuntu0.20.04.1-esm3.md) | Jul 18, 2026 | | Linux | dnsmasq-utils Ubuntu 22.04.1 LTS (jammy) | 2.90-0ubuntu0.22.04.4 | [dnsmasq-utils 2.90-0ubuntu0.22.04.4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-dnsmasq-utils-2.90-0ubuntu0.22.04.4.md) | Jul 18, 2026 | | Linux | dnsmasq-utils Ubuntu 24.04.5 LTS (noble) | 2.90-2ubuntu0.4 | [dnsmasq-utils 2.90-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-noble-dnsmasq-utils-2.90-2ubuntu0.4.md) | Jul 18, 2026 | | Linux | dnsmasq-utils Ubuntu 26.04.1 LTS (resolute) | 2.92-1ubuntu0.4 | [dnsmasq-utils 2.92-1ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-dnsmasq-utils-2.92-1ubuntu0.4.md) | Jun 23, 2026 | --- Data as of 2026-11-09T07:25:28Z UTC. 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