Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS : Dnsmasq vulnerabilities (USN-8542-1)

medium Nessus Plugin ID 327063

Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

The remote Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8542-1 advisory.

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)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

See Also

https://ubuntu.com/security/notices/USN-8542-1

Plugin Details

Severity: Medium

ID: 327063

File Name: ubuntu_USN-8542-1.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 7/15/2026

Updated: 7/15/2026

Supported Sensors: Continuous Assessment, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.77

CVSS v2

Risk Factor: Medium

Base Score: 6.4

Temporal Score: 4.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:P

CVSS Score Source: CVE-2026-12969

CVSS v3

Risk Factor: Medium

Base Score: 5.3

Temporal Score: 4.6

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:20.04:-:lts, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, cpe:/o:canonical:ubuntu_linux:16.04:-:lts, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:dnsmasq, p-cpe:/a:canonical:ubuntu_linux:dnsmasq-base, p-cpe:/a:canonical:ubuntu_linux:dnsmasq-utils, p-cpe:/a:canonical:ubuntu_linux:dnsmasq-base-lua, cpe:/o:canonical:ubuntu_linux:26.04:-:lts

Required KB Items: Host/cpu, Host/Ubuntu, Host/Ubuntu/release, Host/Debian/dpkg-l

Exploit Ease: No known exploits are available

Patch Publication Date: 7/14/2026

Vulnerability Publication Date: 6/22/2026

Reference Information

CVE: CVE-2026-12725, CVE-2026-12969

IAVA: 2026-A-0668

USN: 8542-1