A flaw was found in the X.Org X server. This out-of-bounds read vulnerability in the XKB geometry processing, specifically within the `CheckSetGeom()` and `XkbAddGeomKeyAlias` functions, allows an attacker to read uninitialized or out-of-bounds memory. An attacker with a connection to the X11 server, either locally or remotely, can exploit this without user interaction. This could lead to the disclosure of memory contents or cause a denial of service by crashing the server.

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Advisories

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Fixes

Solution

No solution given by the vendor.


Workaround

To mitigate this vulnerability, restrict access to the X11 server. On systems where a graphical environment is not required, consider disabling the X server entirely by setting the default system target to multi-user mode. For systems requiring the X server, ensure that X11 forwarding is disabled in SSH configurations if not explicitly needed, and restrict direct X11 connections to trusted users and networks through firewall rules. If changes are made to SSH configuration, the `sshd` service must be restarted. If the default system target is changed, a system reboot is required.

History

Wed, 06 May 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Moderate


Tue, 05 May 2026 19:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Tue, 05 May 2026 16:15:00 +0000

Type Values Removed Values Added
Description A flaw was found in the X.Org X server. This out-of-bounds read vulnerability in the XKB geometry processing, specifically within the `CheckSetGeom()` and `XkbAddGeomKeyAlias` functions, allows an attacker to read uninitialized or out-of-bounds memory. An attacker with a connection to the X11 server, either locally or remotely, can exploit this without user interaction. This could lead to the disclosure of memory contents or cause a denial of service by crashing the server.
Title Xwayland: xorg: x.org x server: information disclosure and denial of service via out-of-bounds read in xkb geometry processing.
First Time appeared Redhat
Redhat enterprise Linux
Weaknesses CWE-125
CPEs cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
References
Metrics cvssV3_1

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


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-05-05T18:52:32.853Z

Reserved: 2026-03-25T04:53:13.614Z

Link: CVE-2026-34000

cve-icon Vulnrichment

Updated: 2026-05-05T18:51:44.186Z

cve-icon NVD

Status : Undergoing Analysis

Published: 2026-05-05T16:16:11.647

Modified: 2026-05-05T19:31:10.400

Link: CVE-2026-34000

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-05-05T14:01:15Z

Links: CVE-2026-34000 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-05-05T17:30:06Z

Weaknesses