CVE-2026-93515

.Org Server Present Extension Use-After-Free

Published Oct 28, 2026 CVSS 4.0 · 6.8 Medium EPSS < 1% KEV · Not listed
Description
A use-after-free in present_clear_window_notifies() in the X.org X Server before 21.1.25 and X Wayland before 24.1.14 could be used by malicious X clients to crash or potentially execute code in the X server context.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description A flaw was found in xorg-x11-server. A use-after-free vulnerability, where the application accesses memory after it has already been released, occurs in the Present extension because window notification entries are not properly unlinked before cleaning up window resources. An authenticated local X client can exploit this flaw by creating cross-window notifications and subsequently destroying the target window. Successful exploitation primarily results in a Denial of Service (DoS) via an X server crash, and may potentially lead to information disclosure. A use-after-free in present_clear_window_notifies() in the X.org X Server before 21.1.25 and X Wayland before 24.1.14 could be used by malicious X clients to crash or potentially execute code in the X server context.
Title xorg-x11-server: Present Extension Cross-Window Notify Use-After-Free .Org Server Present Extension Use-After-Free
First Time appeared X.org xorg-x11-server
X.org xwayland
Weaknesses CWE-416
CPEs cpe:2.3:a:x.org:xorg-x11-server:*:*:*:*:*:*:*:*
cpe:2.3:a:x.org:xwayland:*:*:*:*:*:*:*:*
Vendors & Products X.org xorg-x11-server
X.org xwayland
References
Metrics cvssV4_0

{'score': 6.8, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Type Values Removed Values Added
First Time appeared X.org
X.org x Server
Vendors & Products X.org
X.org x Server
Type Values Removed Values Added
Description A flaw was found in xorg-x11-server. A use-after-free vulnerability, where the application accesses memory after it has already been released, occurs in the Present extension because window notification entries are not properly unlinked before cleaning up window resources. An authenticated local X client can exploit this flaw by creating cross-window notifications and subsequently destroying the target window. Successful exploitation primarily results in a Denial of Service (DoS) via an X server crash, and may potentially lead to information disclosure.
Title xorg-x11-server: Present Extension Cross-Window Notify Use-After-Free
Weaknesses CWE-825
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H'}

threat_severity

Moderate

Weaknesses

Sources

Status
PUBLISHED
Assigner
suse
Published
Updated
Nov 6, 2026, 6:33 PM
Reserved
Sep 18, 2026, 8:46 AM
Status
Awaiting Analysis
Published
Oct 28, 2026, 1:17 PM
Modified
Nov 6, 2026, 7:18 PM
Severity
Moderate
Public date
Oct 7, 2026, 12:00 PM