USN-8945-1: XZ Utils vulnerability

Publication date

20 October 2026

Overview

XZ Utils could be made to crash or run programs if it processed specially crafted compressed files under certain conditions.


Packages

  • xz-utils - XZ-format compression utilities

Details

It was discovered that XZ Utils incorrectly handled certain memory
allocation failures when reinitializing decoders for specific compressed
file formats. An attacker could possibly use this issue to trigger an
invalid memory write, resulting in a denial of service or arbitrary code
execution.

It was discovered that XZ Utils incorrectly handled certain memory
allocation failures when reinitializing decoders for specific compressed
file formats. An attacker could possibly use this issue to trigger an
invalid memory write, resulting in a denial of service or arbitrary code
execution.

Update instructions

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

Learn more about how to get the fixes.

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

Ubuntu Release Package Version
26.10 stonking liblzma5 –  5.8.3-1ubuntu1
xz-utils –  5.8.3-1ubuntu1
xzdec –  5.8.3-1ubuntu1
26.04 LTS resolute liblzma5 –  5.8.3-1ubuntu0.1
xz-utils –  5.8.3-1ubuntu0.1
xzdec –  5.8.3-1ubuntu0.1
24.04 LTS noble liblzma5 –  5.6.1+really5.4.5-1ubuntu0.4
xz-utils –  5.6.1+really5.4.5-1ubuntu0.4
xzdec –  5.6.1+really5.4.5-1ubuntu0.4
22.04 LTS jammy liblzma5 –  5.2.5-2ubuntu1.2
xz-utils –  5.2.5-2ubuntu1.2
xzdec –  5.2.5-2ubuntu1.2
20.04 LTS focal liblzma5 –  5.2.4-1ubuntu1.1+esm2  
xz-utils –  5.2.4-1ubuntu1.1+esm2  
xzdec –  5.2.4-1ubuntu1.1+esm2  
18.04 LTS bionic liblzma5 –  5.2.2-1.3ubuntu0.1+esm2  
xz-utils –  5.2.2-1.3ubuntu0.1+esm2  
xzdec –  5.2.2-1.3ubuntu0.1+esm2  
16.04 LTS xenial liblzma5 –  5.1.1alpha+20120614-2ubuntu2.16.04.1+esm3  
xz-utils –  5.1.1alpha+20120614-2ubuntu2.16.04.1+esm3  
xzdec –  5.1.1alpha+20120614-2ubuntu2.16.04.1+esm3  
14.04 LTS trusty liblzma5 –  5.1.1alpha+20120614-2ubuntu2.14.04.1+esm3  
xz-utils –  5.1.1alpha+20120614-2ubuntu2.14.04.1+esm3  
xzdec –  5.1.1alpha+20120614-2ubuntu2.14.04.1+esm3  

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