CVE-2026-93520

X.Org Server XKB ChangeKeycodeRange Heap Out-of-Bounds Write

Published Oct 28, 2026 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
A heap buffer overflow caused by mismatching size calculations between XkbAllocNames and ChangeKeycodeRange in X.org X server before 2.1.25 and XWayland before 24.1.14 could be used by authenticated X clients to crash or potentially execute code in 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': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description A flaw was found in xorg-x11-server. In the X Keyboard Extension (XKB), key name memory is allocated with an insufficient buffer size compared to the maximum supported range. An authenticated local client can exploit this flaw by sending requests that modify the keycode range, triggering a heap-based buffer overflow. This vulnerability can lead to arbitrary code execution or cause a Denial of Service (DoS) by crashing the X server. A heap buffer overflow caused by mismatching size calculations between XkbAllocNames and ChangeKeycodeRange in X.org X server before 2.1.25 and XWayland before 24.1.14 could be used by authenticated X clients to crash or potentially execute code in X server context.
Title xorg-x11-server: XKB ChangeKeycodeRange Heap Out-of-Bounds Write X.Org Server XKB ChangeKeycodeRange Heap Out-of-Bounds Write
First Time appeared X.org xorg-x11-server
X.org xwayland
Weaknesses CWE-122
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
Type Values Removed Values Added
First Time appeared X.org
X.org xorg-server
Vendors & Products X.org
X.org xorg-server
Type Values Removed Values Added
Description A flaw was found in xorg-x11-server. In the X Keyboard Extension (XKB), key name memory is allocated with an insufficient buffer size compared to the maximum supported range. An authenticated local client can exploit this flaw by sending requests that modify the keycode range, triggering a heap-based buffer overflow. This vulnerability can lead to arbitrary code execution or cause a Denial of Service (DoS) by crashing the X server.
Title xorg-x11-server: XKB ChangeKeycodeRange Heap Out-of-Bounds Write
Weaknesses CWE-787
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate

Weaknesses

Sources

Status
PUBLISHED
Assigner
suse
Published
Updated
Nov 7, 2026, 4:55 AM
Reserved
Sep 18, 2026, 8:46 AM
Status
Awaiting Analysis
Published
Oct 28, 2026, 3:17 PM
Modified
Nov 7, 2026, 5:19 AM
Severity
Moderate
Public date
Oct 7, 2026, 12:00 PM