Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.10 : libxml2 vulnerabilities (USN-7974-1)

medium Nessus Plugin ID 296249

Synopsis

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

Description

The remote Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.10 host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-7974-1 advisory.

It was discovered that libxml2 incorrectly handled maliciously crafted SGML catalog files. An attacker could possibly use this issue to cause libxml2 to consume excessive resources, leading to a denial of service. (CVE-2025-8732)

It was discovered that libxml2 incorrectly handled recursive include directories with the RelaxNG parser.
An attacker could possibly use this issue to cause libxml2 to consume excessive resources, leading to a denial of service. (CVE-2026-0989)

Nick Wellnhofer discovered that libxml2 incorrectly parsed catalogs with self-referencing URI delegates.
An attacker could possibly use this issue to cause libxml2 to consume excessive resources, leading to a denial of service. (CVE-2026-0990)

Nick Wellnhofer discovered that libxml2 inefficiently parsed catalogs linked with repeating nextCatalog elements. An attacker could possibly use this issue to cause libxml2 to use excessive resources, leading to a denial of service. (CVE-2026-0992)

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-7974-1

Plugin Details

Severity: Medium

ID: 296249

File Name: ubuntu_USN-7974-1.nasl

Version: 1.1

Type: local

Agent: unix

Published: 1/23/2026

Updated: 1/23/2026

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Low

Base Score: 1.7

Temporal Score: 1.3

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

CVSS Score Source: CVE-2025-8732

CVSS v3

Risk Factor: Low

Base Score: 3.3

Temporal Score: 2.9

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

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

CVSS v4

Risk Factor: Medium

Base Score: 4.8

Threat Score: 1.1

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:14.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:libxml2-16, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, cpe:/o:canonical:ubuntu_linux:25.10, p-cpe:/a:canonical:ubuntu_linux:python-libxml2, cpe:/o:canonical:ubuntu_linux:16.04:-:lts, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:python3-libxml2, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:libxml2, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:libxml2-dev, p-cpe:/a:canonical:ubuntu_linux:libxml2-utils

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

Exploit Ease: No known exploits are available

Patch Publication Date: 1/22/2026

Vulnerability Publication Date: 8/8/2025

Reference Information

CVE: CVE-2025-8732, CVE-2026-0989, CVE-2026-0990, CVE-2026-0992

IAVA: 2025-A-0840

USN: 7974-1