USN-8542-1: Dnsmasq vulnerabilities

Publication date

14 July 2026

Overview

Several security issues were fixed in Dnsmasq.


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  
dnsmasq-base –  2.90-0ubuntu0.20.04.1+esm3  
dnsmasq-base-lua –  2.90-0ubuntu0.20.04.1+esm3  
dnsmasq-utils –  2.90-0ubuntu0.20.04.1+esm3  
18.04 LTS bionic dnsmasq –  2.90-0ubuntu0.18.04.1+esm4  
dnsmasq-base –  2.90-0ubuntu0.18.04.1+esm4  
dnsmasq-base-lua –  2.90-0ubuntu0.18.04.1+esm4  
dnsmasq-utils –  2.90-0ubuntu0.18.04.1+esm4  
16.04 LTS xenial dnsmasq –  2.90-0ubuntu0.16.04.1+esm4  
dnsmasq-base –  2.90-0ubuntu0.16.04.1+esm4  
dnsmasq-base-lua –  2.90-0ubuntu0.16.04.1+esm4  
dnsmasq-utils –  2.90-0ubuntu0.16.04.1+esm4  

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