RHSA-2026:36083: Important: xorg-x11-server security update

Published Jul 7, 2026
·
Updated

Important: xorg-x11-server security update

Other sources

X.Org is an open-source implementation of the X Window System. It provides the basic low-level functionality that full-fledged graphical user interfaces are designed upon.Security Fix(es): xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in font alias resolution due to libXfont2 name length mismatch (CVE-2026-50256) xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in miSyncDestroyFence() (CVE-2026-50257) xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in XKB key types due to unchecked shift levels (CVE-2026-50258) xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in XKB SetMap request via mapWidths indexing (CVE-2026-50259) xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in FreeCounter() (CVE-2026-50260) xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in SyncChangeCounter() (CVE-2026-50261) xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: out-of-bounds read/write in GLX ChangeDrawableAttributes (CVE-2026-50262) xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free information disclosure in CreateSaverWindow() (CVE-2026-50263) xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: out-of-bounds heap write in DRI2 DRIGetBuffers/DRIGetBuffersWithFormat (CVE-2026-50264) 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.

— Red Hat

Affected Software

15 affected componentsFixes available
Red Hat Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, big endian
Red Hat Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, little endian
Red Hat Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems)
Red Hat Red Hat Enterprise Linux Server - Extended Life Cycle Support
redhat/xorg-x11-server<1.20.4-35.el7_9
1.20.4-35.el7_9
redhat/xorg-x11-server-common<1.20.4-35.el7_9
1.20.4-35.el7_9
redhat/xorg-x11-server-debuginfo<1.20.4-35.el7_9
1.20.4-35.el7_9
redhat/xorg-x11-server-debuginfo<1.20.4-35.el7_9
1.20.4-35.el7_9
redhat/xorg-x11-server-devel<1.20.4-35.el7_9
1.20.4-35.el7_9
redhat/xorg-x11-server-devel<1.20.4-35.el7_9
1.20.4-35.el7_9
redhat/xorg-x11-server-source<1.20.4-35.el7_9
1.20.4-35.el7_9
redhat/xorg-x11-server-common<1.20.4-35.el7_9
1.20.4-35.el7_9
redhat/xorg-x11-server-common<1.20.4-35.el7_9
1.20.4-35.el7_9
redhat/xorg-x11-server-debuginfo<1.20.4-35.el7_9
1.20.4-35.el7_9
redhat/xorg-x11-server-devel<1.20.4-35.el7_9
1.20.4-35.el7_9

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade redhat/xorg-x11-server to a version that resolves this vulnerability.

    Fixed in 1.20.4-35.el7_9
  2. Upgrade

    Upgrade redhat/xorg-x11-server-common to a version that resolves this vulnerability.

    Fixed in 1.20.4-35.el7_9
  3. Upgrade

    Upgrade redhat/xorg-x11-server-debuginfo to a version that resolves this vulnerability.

    Fixed in 1.20.4-35.el7_9
  4. Upgrade

    Upgrade redhat/xorg-x11-server-devel to a version that resolves this vulnerability.

    Fixed in 1.20.4-35.el7_9
  5. Upgrade

    Upgrade redhat/xorg-x11-server-source to a version that resolves this vulnerability.

    Fixed in 1.20.4-35.el7_9
  6. Upgrade

    Upgrade xorg-x11-server/xorg-x11-server-Xwayland to a version that resolves this vulnerability.

    Patch CVE-2026-50256
  7. Upgrade

    Upgrade xorg-x11-server/xorg-x11-server-Xwayland to a version that resolves this vulnerability.

    Patch CVE-2026-50264
  8. Upgrade

    Upgrade xorg-x11-server/xorg-x11-server-Xwayland to a version that resolves this vulnerability.

    Patch CVE-2026-50262
  9. Upgrade

    Upgrade xorg-x11-server/xorg-x11-server-Xwayland to a version that resolves this vulnerability.

    Patch CVE-2026-50259
  10. Upgrade

    Upgrade xorg-x11-server/xorg-x11-server-Xwayland to a version that resolves this vulnerability.

    Patch CVE-2026-50258
  11. Upgrade

    Upgrade xorg-x11-server/xorg-x11-server-Xwayland to a version that resolves this vulnerability.

    Patch CVE-2026-50260
  12. Upgrade

    Upgrade xorg-x11-server/xorg-x11-server-Xwayland to a version that resolves this vulnerability.

    Patch CVE-2026-50261
  13. Upgrade

    Upgrade xorg-x11-server/xorg-x11-server-Xwayland to a version that resolves this vulnerability.

    Patch CVE-2026-50257
  14. Upgrade

    Upgrade xorg-x11-server/xorg-x11-server-Xwayland to a version that resolves this vulnerability.

    Patch CVE-2026-50263

Event History

Jul 7, 2026
Advisory Published
via Red Hat·12:00 AM
Data Sourced
via Red Hat·12:00 AM
RemedyDescriptionAffected Software
Advisory Published
via Red Hat·05:32 AM
Data Sourced
via Red Hat·05:32 AM
Severity
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Frequently Asked Questions

1

What is the severity of RHSA-2026:36083?

The severity of RHSA-2026:36083 is classified as high with a score of 7.

2

How do I fix RHSA-2026:36083?

To fix RHSA-2026:36083, update the affected xorg-x11-server packages to their latest versions provided by Red Hat.

3

What vulnerabilities are addressed in RHSA-2026:36083?

RHSA-2026:36083 addresses vulnerabilities including buffer overflow and use after free in the xorg-x11-server.

4

Which software components are affected by RHSA-2026:36083?

The affected software components include xorg-x11-server-common, xorg-x11-server-debuginfo, and xorg-x11-server-devel.

5

When was RHSA-2026:36083 published?

RHSA-2026:36083 was published on July 7, 2026.

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