RHSA-2026:5221 - Security Advisory

Topic

An update for python3 is now available for Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On.

Red Hat Product Security has rated this update as having a security impact of Moderate. 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):

• cpython: IMAP command injection in user-controlled commands (CVE-2025-15366)
• cpython: POP3 command injection in user-controlled commands (CVE-2025-15367)
• cpython: email header injection due to unquoted newlines (CVE-2026-1299)

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

• Red Hat Enterprise Linux for x86_64 - Extended Update Support Extension 8.4 x86_64
• Red Hat Enterprise Linux Server - AUS 8.4 x86_64

Fixes

• BZ - 2431368 - CVE-2025-15366 cpython: IMAP command injection in user-controlled commands
• BZ - 2431373 - CVE-2025-15367 cpython: POP3 command injection in user-controlled commands
• BZ - 2432437 - CVE-2026-1299 cpython: email header injection due to unquoted newlines

CVEs

• CVE-2025-15366
• CVE-2025-15367
• CVE-2026-1299

References

• https://access.redhat.com/security/updates/classification/#moderate