Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: use-after-free in syncchangecounter()_CVE-2026-50261

7.8 / 10

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Description

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.

Basic Information

ID CVE-2026-50261

Source redhat

Published Jun 5, 2026 at 10:36

Affected Product

Vendor Red Hat

Product Red Hat Enterprise Linux 10

CWE Classification

CWE-416

References

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    "published": "2026-06-05T10:36:33.418Z",
    "modified": "2026-06-05T10:36:33.418Z",
    "type": "cve",
    "title": "Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: use-after-free in syncchangecounter()",
    "source": "redhat",
    "references": "https://access.redhat.com/security/cve/CVE-2026-50261\nhttps://bugzilla.redhat.com/show_bug.cgi?id=2485386\nhttps://gitlab.freedesktop.org/xorg/xserver/-/commit/bdd7bf57af208b1ddf57d4683d67104443b44812\nhttps://lists.x.org/archives/xorg-announce/2026-June/003702.html\nhttps://redhat.atlassian.net/browse/PSIRTSUPT-16950",
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