Issued:
2026-01-26
Updated:
2026-01-26

RHSA-2026:1226 - Important: python3.12-urllib3 security update

Synopsis

Important: python3.12-urllib3 security update

Type/Severity

Security Advisory Important

Topic

An update for python3.12-urllib3 is now available for Red Hat Enterprise Linux 8.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

  • urllib3: urllib3: Unbounded decompression chain leads to resource exhaustion (CVE-2025-66418)

  • urllib3: urllib3 Streaming API improperly handles highly compressed data (CVE-2025-66471)

  • urllib3: urllib3 vulnerable to decompression-bomb safeguard bypass when following HTTP redirects (streaming API) (CVE-2026-21441)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

ProductVersionArch
Red Hat Enterprise Linux for x86_648x86_64
Red Hat Enterprise Linux for Power, little endian8ppc64le
Red Hat Enterprise Linux for IBM z Systems8s390x
Red Hat Enterprise Linux for ARM 648aarch64

Updated Packages

  • python3.12-urllib3-1.26.19-2.el8_10.noarch.rpm
  • python3.12-urllib3-1.26.19-2.el8_10.src.rpm

Fixes

CVEs

References

Additional information