USN-8956-2: Brotli vulnerability

Publication date

27 October 2026

Overview

Brotli could be made to crash or run programs if it received specially crafted input.


Packages

  • brotli - lossless compression algorithm and format (command line utility)

Details

USN-8956-1 fixed a vulnerability in Brotli. This update provides the
corresponding fixes for Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and
Ubuntu 20.04 LTS.

Original advisory details:

It was discovered that Brotli incorrectly handled certain compressed
streams. A remote attacker could possibly use this issue to cause a
denial of service or execute arbitrary code.

USN-8956-1 fixed a vulnerability in Brotli. This update provides the
corresponding fixes for Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and
Ubuntu 20.04 LTS.

Original advisory details:

It was discovered that Brotli incorrectly handled certain compressed
streams. A remote attacker could possibly use this issue to cause a
denial of service or execute arbitrary code.

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
20.04 LTS focal brotli –  1.0.7-6ubuntu0.1+esm1  
libbrotli1 –  1.0.7-6ubuntu0.1+esm1  
python3-brotli –  1.0.7-6ubuntu0.1+esm1  
18.04 LTS bionic brotli –  1.0.3-1ubuntu1.3+esm1  
libbrotli1 –  1.0.3-1ubuntu1.3+esm1  
python-brotli –  1.0.3-1ubuntu1.3+esm1  
python3-brotli –  1.0.3-1ubuntu1.3+esm1  
16.04 LTS xenial brotli –  1.0.3-1ubuntu1~16.04.2+esm1  
libbrotli1 –  1.0.3-1ubuntu1~16.04.2+esm1  
python-brotli –  1.0.3-1ubuntu1~16.04.2+esm1  
python3-brotli –  1.0.3-1ubuntu1~16.04.2+esm1  

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