RHSA-2026:18957 - Security Advisory

Topic

An update for python3.11 is now available for Red Hat Enterprise Linux 9.

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: wsgiref.headers.Headers allows header newline injection in Python (CVE-2026-0865)

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.

Additional Changes:

For detailed information on changes in this release, see the Red Hat Enterprise Linux 9 Release Notes linked from 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 9 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 9.8 x86_64
• Red Hat Enterprise Linux for IBM z Systems 9 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.8 s390x
• Red Hat Enterprise Linux for Power, little endian 9 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 9.8 ppc64le
• Red Hat Enterprise Linux for ARM 64 9 aarch64
• Red Hat Enterprise Linux for ARM 64 - Extended Update Support 9.8 aarch64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.8 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.8 x86_64
• Red Hat CodeReady Linux Builder for x86_64 9 x86_64
• Red Hat CodeReady Linux Builder for Power, little endian 9 ppc64le
• Red Hat CodeReady Linux Builder for ARM 64 9 aarch64
• Red Hat CodeReady Linux Builder for IBM z Systems 9 s390x
• Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support 9.8 x86_64
• Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support 9.8 ppc64le
• Red Hat CodeReady Linux Builder for IBM z Systems - Extended Update Support 9.8 s390x
• Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support 9.8 aarch64
• Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.8 aarch64
• Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.8 s390x
• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.8 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.8 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.8 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.8 s390x

Fixes

• BZ - 2431367 - CVE-2026-0865 cpython: wsgiref.headers.Headers allows header newline injection in Python

CVEs

• CVE-2026-0865

References

• https://access.redhat.com/security/updates/classification/#moderate
• https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/9/html/9.8_release_notes/index