CVE-2026-12725

Publication date 22 June 2026

Last updated 16 July 2026

Ubuntu priority

Cvss 3 Severity Score

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.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
dnsmasq	26.04 LTS resolute	Fixed 2.92-1ubuntu0.4
	25.10 questing	Ignored end of life, was needs-triage
	24.04 LTS noble	Fixed 2.90-2ubuntu0.4
	22.04 LTS jammy	Fixed 2.90-0ubuntu0.22.04.4
	20.04 LTS focal	Fixed 2.90-0ubuntu0.20.04.1+esm3
	18.04 LTS bionic	Fixed 2.90-0ubuntu0.18.04.1+esm4
	16.04 LTS xenial	Fixed 2.90-0ubuntu0.16.04.1+esm4
	14.04 LTS trusty	Not affected

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Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
dnsmasq	Upstream: 36d081e

Severity score breakdown

CVSS version: CVSS v3.0

Base score 5.9 · Medium

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	High
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality impact	None
Integrity impact	None
Availability impact	High

Scores

Parameter	Value
Base score	5.9 · Medium
Exploitability score	-
Impact score	-

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

USN-8542-1
Dnsmasq vulnerabilities
14 July 2026

Other references

https://www.cve.org/CVERecord?id=CVE-2026-12725