Ubuntu Security Notices USN-8542-1 USN-8542-1: Dnsmasq vulnerabilities Publication date 14 July 2026 Overview Several security issues were fixed in Dnsmasq. Releases 26.04 LTS 24.04 LTS 22.04 LTS 20.04 LTS 18.04 LTS 16.04 LTS Open side navigation Close side navigation Packages Details Update instructions References Packages dnsmasq - Small caching DNS proxy and DHCP/TFTP server Details Yiwei Hou discovered that Dnsmasq incorrectly handled logging of DS or DNSKEY. A remote attacker could possibly use this issue to cause a denial of service. ( CVE-2026-12725 ) It was discovered that Dnsmasq incorrectly validated the length of fixed-length DNS record fields when parsing NS section records. A remote attacker could possibly use this issue to cause Dnsmasq to read out of bounds, possibly exposing sensitive information. ( CVE-2026-12969 ) Yiwei Hou discovered that Dnsmasq incorrectly handled logging of DS or DNSKEY. A remote attacker could possibly use this issue to cause a denial of service. ( CVE-2026-12725 ) It was discovered that Dnsmasq incorrectly validated the length of fixed-length DNS record fields when parsing NS section records. A remote attacker could possibly use this issue to cause Dnsmasq to read out of bounds, possibly exposing sensitive information. ( CVE-2026-12969 ) Update instructions After a standard system update you need to restart dnsmasq to make all the necessary changes. Learn more about how to get the fixes. The problem can be corrected by updating your system to the following package versions: Ubuntu Release Package Version 26.04 LTS resolute dnsmasq – 2.92-1ubuntu0.4 dnsmasq-base – 2.92-1ubuntu0.4 dnsmasq-base-lua – 2.92-1ubuntu0.4 dnsmasq-utils – 2.92-1ubuntu0.4 24.04 LTS noble dnsmasq – 2.90-2ubuntu0.4 dnsmasq-base – 2.90-2ubuntu0.4 dnsmasq-base-lua – 2.90-2ubuntu0.4 dnsmasq-utils – 2.90-2ubuntu0.4 22.04 LTS jammy dnsmasq – 2.90-0ubuntu0.22.04.4 dnsmasq-base – 2.90-0ubuntu0.22.04.4 dnsmasq-base-lua – 2.90-0ubuntu0.22.04.4 dnsmasq-utils – 2.90-0ubuntu0.22.04.4 20.04 LTS focal dnsmasq – 2.90-0ubuntu0.20.04.1+esm3 Ubuntu Pro Fix available with Ubuntu Pro . dnsmasq-base – 2.90-0ubuntu0.20.04.1+esm3 Ubuntu Pro Fix available with Ubuntu Pro . dnsmasq-base-lua – 2.90-0ubuntu0.20.04.1+esm3 Ubuntu Pro Fix available with Ubuntu Pro . dnsmasq-utils – 2.90-0ubuntu0.20.04.1+esm3 Ubuntu Pro Fix available with Ubuntu Pro . 18.04 LTS bionic dnsmasq – 2.90-0ubuntu0.18.04.1+esm4 Ubuntu Pro Fix available with Ubuntu Pro . dnsmasq-base – 2.90-0ubuntu0.18.04.1+esm4 Ubuntu Pro Fix available with Ubuntu Pro . dnsmasq-base-lua – 2.90-0ubuntu0.18.04.1+esm4 Ubuntu Pro Fix available with Ubuntu Pro . dnsmasq-utils – 2.90-0ubuntu0.18.04.1+esm4 Ubuntu Pro Fix available with Ubuntu Pro . 16.04 LTS xenial dnsmasq – 2.90-0ubuntu0.16.04.1+esm4 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. dnsmasq-base – 2.90-0ubuntu0.16.04.1+esm4 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. dnsmasq-base-lua – 2.90-0ubuntu0.16.04.1+esm4 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. dnsmasq-utils – 2.90-0ubuntu0.16.04.1+esm4 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. Reduce your security exposure Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines. Get Ubuntu Pro References CVE-2026-12969 CVE-2026-12725 CVE-2026-12969 CVE-2026-12725