USN-7945-1: Libxslt vulnerability

USN-7945-1: Libxslt vulnerability

Publication date: 7 January 2026
Overview: Libxslt could be made to crash or exhibit undefined behavior if it opened a specially crafted file.

Packages
libxslt - XSLT processing library

Details
Ivan Fratric discovered that Libxslt was vulnerable to type confusion when
performing XML transformations. An attacker could possibly use this issue
to cause Libxslt to crash or corrupt memory, causing a denial of service or
undefined behavior.

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

25.04 plucky

• libxslt1.1 – 1.1.39-0exp1ubuntu4.1
• xsltproc – 1.1.39-0exp1ubuntu4.1

24.04 LTS noble

• libxslt1.1 – 1.1.39-0exp1ubuntu0.24.04.3
• xsltproc – 1.1.39-0exp1ubuntu0.24.04.3

22.04 LTS jammy

• libxslt1.1 – 1.1.34-4ubuntu0.22.04.5
• xsltproc – 1.1.34-4ubuntu0.22.04.5

20.04 LTS focal

• libxslt1.1 – 1.1.34-4ubuntu0.20.04.3+esm2
• xsltproc – 1.1.34-4ubuntu0.20.04.3+esm2

18.04 LTS bionic

• libxslt1.1 – 1.1.29-5ubuntu0.3+esm3
• xsltproc – 1.1.29-5ubuntu0.3+esm3

16.04 LTS xenial

• libxslt1.1 – 1.1.28-2.1ubuntu0.3+esm4
• xsltproc – 1.1.28-2.1ubuntu0.3+esm4

14.04 LTS trusty

• libxslt1.1 – 1.1.28-2ubuntu0.2+esm5
• xsltproc – 1.1.28-2ubuntu0.2+esm5