---
id: CVE-2026-93524
title: X.Org Server XKB SetMap Key Width/Action Count Desync Out-Of-Bounds Read
summary: "A buffer overread in\_CheckKeySyms() in X.Org X Server before 21.1.25 and XWayland before 24.1.14 could be used by authenticated X clients to leak small amounts of information from X server memory or potentially crash the X server."
severity: medium
cvss: 6.9
cvssVector: 'CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N'
cvssSource: cna
cwe:
  - CWE-126
vendor: x.org
product: xorg-x11-server
affected:
  - xorg-x11-server < 21.1.25
  - xwayland < 24.1.14
published: '2026-10-28'
updated: '2026-10-28'
sourceUpdated: '2026-10-28T16:24:52.508Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-93524'
references:
  - url: >-
      https://gitlab.freedesktop.org/xorg/xserver/-/commit/cea71d0273e4d5092aa9c6a8a770734c8935c02e
tags:
  - cve.org
ingestedAt: '2026-10-28T17:14:44.491Z'
---

## Overview

A buffer overread in CheckKeySyms() in X.Org X Server before 21.1.25 and XWayland before 24.1.14 could be used by authenticated X clients to leak small amounts of information from X server memory or potentially crash the X server.

## Affected

- `xorg-x11-server < 21.1.25`
- `xwayland < 24.1.14`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.