========================================================================== Ubuntu Security Notice USN-8542-1 July 14, 2026
dnsmasq vulnerabilities
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 26.04 LTS
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
Summary:
Several security issues were fixed in Dnsmasq.
Software Description:
- 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)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 26.04 LTS
dnsmasq 2.92-1ubuntu0.4
dnsmasq-base 2.92-1ubuntu0.4
dnsmasq-base-lua 2.92-1ubuntu0.4
dnsmasq-utils 2.92-1ubuntu0.4
Ubuntu 24.04 LTS
dnsmasq 2.90-2ubuntu0.4
dnsmasq-base 2.90-2ubuntu0.4
dnsmasq-base-lua 2.90-2ubuntu0.4
dnsmasq-utils 2.90-2ubuntu0.4
Ubuntu 22.04 LTS
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
Ubuntu 20.04 LTS
dnsmasq 2.90-0ubuntu0.20.04.1+esm3
Available with Ubuntu Pro
dnsmasq-base 2.90-0ubuntu0.20.04.1+esm3
Available with Ubuntu Pro
dnsmasq-base-lua 2.90-0ubuntu0.20.04.1+esm3
Available with Ubuntu Pro
dnsmasq-utils 2.90-0ubuntu0.20.04.1+esm3
Available with Ubuntu Pro
Ubuntu 18.04 LTS
dnsmasq 2.90-0ubuntu0.18.04.1+esm4
Available with Ubuntu Pro
dnsmasq-base 2.90-0ubuntu0.18.04.1+esm4
Available with Ubuntu Pro
dnsmasq-base-lua 2.90-0ubuntu0.18.04.1+esm4
Available with Ubuntu Pro
dnsmasq-utils 2.90-0ubuntu0.18.04.1+esm4
Available with Ubuntu Pro
Ubuntu 16.04 LTS
dnsmasq 2.90-0ubuntu0.16.04.1+esm4
Available with Ubuntu Pro
dnsmasq-base 2.90-0ubuntu0.16.04.1+esm4
Available with Ubuntu Pro
dnsmasq-base-lua 2.90-0ubuntu0.16.04.1+esm4
Available with Ubuntu Pro
dnsmasq-utils 2.90-0ubuntu0.16.04.1+esm4
Available with Ubuntu Pro
After a standard system update you need to restart dnsmasq to make
all the necessary changes.
References:
https://ubuntu.com/security/notices/USN-8542-1
CVE-2026-12725, CVE-2026-12969
Package Information:
https://launchpad.net/ubuntu/+source/dnsmasq/2.92-1ubuntu0.4
https://launchpad.net/ubuntu/+source/dnsmasq/2.90-2ubuntu0.4
https://launchpad.net/ubuntu/+source/dnsmasq/2.90-0ubuntu0.22.04.4
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