Expired Pointer Dereference Affecting xorg-x11-server-common package, versions <0:1.20.11-18.el8_8


Severity

Recommended
0.0
high
0
10

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.18% (8th percentile)

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  • Snyk IDSNYK-RHEL8-XORGX11SERVERCOMMON-17074635
  • published29 May 2026
  • disclosed23 Apr 2026

Introduced: 23 Apr 2026

CVE-2026-34001  (opens in a new tab)
CWE-825  (opens in a new tab)

How to fix?

Upgrade RHEL:8 xorg-x11-server-common to version 0:1.20.11-18.el8_8 or higher.
This issue was patched in RHSA-2026:21742.

NVD Description

Note: Versions mentioned in the description apply only to the upstream xorg-x11-server-common package and not the xorg-x11-server-common package as distributed by RHEL. See How to fix? for RHEL:8 relevant fixed versions and status.

A flaw was found in the X.Org X server. This use-after-free vulnerability occurs in the XSYNC fence triggering logic, specifically within the miSyncTriggerFence() function. An attacker with access to the X11 server can exploit this without user interaction, leading to a server crash and potentially enabling memory corruption. This could result in a denial of service or further compromise of the system.

CVSS Base Scores

version 3.1