Ubuntu 26.04 LTS Security Advisory USN-8379-1 Urllib3 Critical Issues

ubuntu

June 3, 2026

Several security issues were fixed in urllib3.

Summary

Several security issues were fixed in urllib3.

Software Description:

- python-urllib3: HTTP library with thread-safe connection pooling

Details:

It was discovered that urllib3 incorrectly handled cross-origin redirects

in ProxyManager. A remote attacker could possibly use this issue to obtain

sensitive information. (CVE-2026-44431)

It was discovered that urllib3 incorrectly handled decompression of

specially crafted responses. A remote attacker could possibly use this

issue to cause urllib3 to consume resources, leading to a denial of

service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-44432)

Topics Covered

security advisory denial of service critical Ubuntu cross-origin urllib3

Update Instructions

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

Ubuntu 26.04 LTS
  python3-urllib3                 2.6.3-1ubuntu1.1

Ubuntu 25.10
  python3-urllib3                 2.3.0-3ubuntu0.6

Ubuntu 24.04 LTS
  python3-urllib3                 2.0.7-1ubuntu0.7

Ubuntu 22.04 LTS
  python3-urllib3                 1.26.5-1~exp1ubuntu0.7

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