USN-7974-1: libxml2 vulnerabilities

USN-7974-1: libxml2 vulnerabilities

Publication date: 22 January 2026
Overview: Several security issues were fixed in libxml2.

Packages
libxml2 - GNOME XML library

Details
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)

Update instructions
In general, a standard system update will make all the necessary changes.

The problem can be corrected by updating your system to the following package versions:

• 25.10 questing libxml2-16 – 2.14.5+dfsg-0.2ubuntu0.1
• 24.04 LTS noble libxml2 – 2.9.14+dfsg-1.3ubuntu3.7
• 22.04 LTS jammy libxml2 – 2.9.13+dfsg-1ubuntu0.11
• 20.04 LTS focal libxml2 – 2.9.10+dfsg-5ubuntu0.20.04.10+esm4
• 18.04 LTS bionic libxml2 – 2.9.4+dfsg1-6.1ubuntu1.9+esm7
• 16.04 LTS xenial libxml2 – 2.9.3+dfsg1-1ubuntu0.7+esm12
• 14.04 LTS trusty libxml2 – 2.9.1+dfsg1-3ubuntu4.13+esm11