USN-7694-1: libxml2 vulnerabilities

USN-7694-1: libxml2 vulnerabilities
Publication date: 14 August 2025
Overview: Several security issues were fixed in libxml2.
Releases: 25.04 , 24.04 LTS , 22.04 LTS , 20.04 LTS, 18.04 LTS, 16.04 LTS ,14.04 LTS

Packages

• libxml2 - GNOME XML library

Details
Ahmed Lekssays discovered that libxml2 did not properly perform certain
mathematical operations, leading to an integer overflow. An attacker
could possibly use this issue to cause a crash, resulting in a denial of
service, or possibly execute arbitrary code. (CVE-2025-6021)

Ahmed Lekssays discovered that libxml2 did not properly validate the size
of an untrusted input stream. An attacker could possibly use this issue
to cause a crash, resulting in a denial of service, or possibly execute
arbitrary code. (CVE-2025-6170)

Nikita Sveshnikov discovered that libxml2 did not properly handle certain
XPath expressions, leading to a use-after-free vulnerability. An attacker
could potentially exploit this issue to cause a denial of service.
(CVE-2025-49794)

Nikita Sveshnikov discovered that libxml2 contained a type confusion
vulnerability when parsing specially crafted XML documents. An attacker
could potentially exploit this issue to cause a denial of service.
(CVE-2025-49796)

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

25.04 plucky:

• libxml2 – 2.12.7+dfsg+really2.9.14-0.4ubuntu0.2
• python3-libxml2 – 2.12.7+dfsg+really2.9.14-0.4ubuntu0.2
  24.04 noble:
• libxml2 – 2.9.14+dfsg-1.3ubuntu3.4
• python3-libxml2 – 2.9.14+dfsg-1.3ubuntu3.4
  22.04 jammy
• libxml2 – 2.9.13+dfsg-1ubuntu0.8
• python3-libxml2 – 2.9.13+dfsg-1ubuntu0.8
  20.04 focal
• libxml2 – 2.9.10+dfsg-5ubuntu0.20.04.10+esm1
• python3-libxml2 – 2.9.10+dfsg-5ubuntu0.20.04.10+esm1
  18.04 bionic
• libxml2 – 2.9.4+dfsg1-6.1ubuntu1.9+esm4
• python-libxml2 – 2.9.4+dfsg1-6.1ubuntu1.9+esm4
• python3-libxml2 – 2.9.4+dfsg1-6.1ubuntu1.9+esm4
  16.04 xenial
• libxml2 – 2.9.3+dfsg1-1ubuntu0.7+esm9
• python-libxml2 – 2.9.3+dfsg1-1ubuntu0.7+esm9
  14.04 trusty
• libxml2 – 2.9.1+dfsg1-3ubuntu4.13+esm8
• python-libxml2 – 2.9.1+dfsg1-3ubuntu4.13+esm8