---
id: "CVE-2026-93524"
kind: "vulnerability"
aliases: ["CVE-2026-93524"]
title: "X.Org X Server: keyboard map check lets clients read server memory"
severity: "medium"
cvss: 6.9
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["desktop", "infrastructure", "linux", "x11", "xwayland"]
not_affected_if: ["no-untrusted-x-clients", "wayland-only"]
published_at: "2026-10-28T17:18:53+00:00"
first_seen_at: "2026-10-28T17:34:10+00:00"
updated_at: "2026-10-28T17:36:24+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-93524", "first_seen_at": "2026-10-28T17:34:10+00:00"}]
---

# X.Org X Server: keyboard map check lets clients read server memory

A buffer overread in CheckKeySyms() in X.Org X Server before 21.1.25 and XWayland before 24.1.14 lets an authenticated X client read small amounts of server memory. It can also crash the X server.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `Xorg -version` or `X -version` to see the X.Org Server version.
- Run `Xwayland -version` to check the XWayland version.

## Fix

- Upgrade X.Org X Server to `21.1.25` or later.
- Upgrade XWayland to `24.1.14` or later.

## Timeline

- 2026-10-28T17:34:10+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-93524

## From the sources

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.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_