RHSA-2026:52398 - Security Advisory

Topic

An update for xorg-x11-server-Xwayland is now available for Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions.

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

Xwayland is an X server for running X clients under Wayland.

Security Fix(es):

• xorg: X11: xserver: X.org: glamor Font Atlas Heap Buffer Overflow (CVE-2026-55999)
• X.org: xorg-x11-server: GLX contextTags Use-After-Free in CommonMakeCurrent() (CVE-2026-56000)

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 Server - AUS 9.4 x86_64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.4 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.4 x86_64
• Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.4 aarch64
• Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.4 s390x
• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.4 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.4 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.4 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.4 s390x

Fixes

• BZ - 2496165 - CVE-2026-55999 xorg: X11: xserver: X.org: glamor Font Atlas Heap Buffer Overflow
• BZ - 2496193 - CVE-2026-56000 X.org: xorg-x11-server: GLX contextTags Use-After-Free in CommonMakeCurrent()

CVEs

• CVE-2026-55999
• CVE-2026-56000

References

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