---
id: CVE-2026-93520
title: X.Org Server XKB ChangeKeycodeRange Heap Out-of-Bounds Write
summary: "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 exe…"
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-122
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: '2026-10-28T14:59:50.140Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-93520'
references:
  - url: >-
      https://gitlab.freedesktop.org/xorg/xserver/-/commit/b941a473e06f26a407a9adb15759be79f7418e86
tags:
  - cve.org
ingestedAt: '2026-10-28T16:13:50.592Z'
---

## Overview

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.

## 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.