CVE-2026-50261

A use-after-free flaw was found in the X.Org X server and Xwayland in SyncChangeCounter(). A client that sets up multiple SyncCounters can trigger a use-after-free when destroying those counters via a second client connection while changing those counters. This may be used to crash the server, or for privilege escalation if the X server runs as root.
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:x.org:x_server:*:*:*:*:*:*:*:*
cpe:2.3:a:x.org:xwayland:*:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*

History

15 Jun 2026, 13:46

Type Values Removed Values Added
CPE cpe:2.3:a:x.org:xwayland:*:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:a:x.org:x_server:*:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
First Time Redhat enterprise Linux
Redhat
X.org
X.org xwayland
X.org x Server
References () https://access.redhat.com/security/cve/CVE-2026-50261 - () https://access.redhat.com/security/cve/CVE-2026-50261 - Third Party Advisory
References () https://bugzilla.redhat.com/show_bug.cgi?id=2485386 - () https://bugzilla.redhat.com/show_bug.cgi?id=2485386 - Issue Tracking, Third Party Advisory
References () https://gitlab.freedesktop.org/xorg/xserver/-/commit/bdd7bf57af208b1ddf57d4683d67104443b44812 - () https://gitlab.freedesktop.org/xorg/xserver/-/commit/bdd7bf57af208b1ddf57d4683d67104443b44812 - Patch
References () https://lists.x.org/archives/xorg-announce/2026-June/003702.html - () https://lists.x.org/archives/xorg-announce/2026-June/003702.html - Mailing List, Vendor Advisory
References () https://redhat.atlassian.net/browse/PSIRTSUPT-16950 - () https://redhat.atlassian.net/browse/PSIRTSUPT-16950 - Permissions Required

05 Jun 2026, 12:16

Type Values Removed Values Added
New CVE

Information

Published : 2026-06-05 12:16

Updated : 2026-06-15 13:46


NVD link : CVE-2026-50261

Mitre link : CVE-2026-50261

CVE.ORG link : CVE-2026-50261


JSON object : View

Products Affected

x.org

  • x_server
  • xwayland

redhat

  • enterprise_linux
CWE
CWE-416

Use After Free