USN-7955-2: urllib3 regression

Publication date

19 January 2026

Overview

USN-7955-1 introduced a regression in urllib3


Packages

Details

USN-7955-1 fixed vulnerabilities in urllib3. The update introduced a
regression in response streaming on Ubuntu 20.04 LTS and Ubuntu 22.04 LTS.
This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

It was discovered that urllib3 incorrectly handled decompression during
HTTP redirects. An attacker could possibly use this issue to cause urllib3
to use excessive resources, causing a denial of service.

USN-7955-1 fixed vulnerabilities in urllib3. The update introduced a
regression in response streaming on Ubuntu 20.04 LTS and Ubuntu 22.04 LTS.
This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

It was discovered that urllib3 incorrectly handled decompression during
HTTP redirects. An attacker could possibly use this issue to cause urllib3
to use excessive resources, causing a denial of service.

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
22.04 LTS jammy python3-urllib3 –  1.26.5-1~exp1ubuntu0.6
20.04 LTS focal python3-urllib3 –  1.25.8-2ubuntu0.4+esm4  

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