---
id: "CVE-2026-109093"
page: "https://infrastack.ai/live/CVE-2026-109093"
kind: "vulnerability"
aliases: ["CVE-2026-109093"]
title: "X.Org xwayland and X server: stack overflow lets clients run code"
severity: "high"
cvss: 8.5
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["desktop", "infrastructure", "linux", "x.org", "xwayland"]
not_affected_if: ["fixed-version-installed", "wayland-only-no-xwayland"]
published_at: "2026-11-13T15:17:29+00:00"
first_seen_at: "2026-11-13T15:46:15+00:00"
updated_at: "2026-11-13T15:48:19+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-109093", "first_seen_at": "2026-11-13T15:46:15+00:00"}]
exploit_sources: []
---

# X.Org xwayland and X server: stack overflow lets clients run code

Link for people: https://infrastack.ai/live/CVE-2026-109093 (this .md is for agents)

A stack buffer overflow in the XTEST fake-input handling of X.Org xwayland before 24.1.15 and the X server before 21.1.26 lets an authenticated client crash the server. The same flaw could let that client execute code inside the X server.

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

## How to check

- Check the installed X server version with `Xorg -version` or `Xwayland -version`.
- Compare the result against `21.1.26` for the X server and `24.1.15` for xwayland.

## Fix

- X server: move to `21.1.26` or later.
- xwayland: move to `24.1.15` or later.

## Timeline

- 2026-11-13T15:46:15+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-109093

## From the sources

A stack buffer overflow in  ProcXTestFakeInput DeviceValuator handling in X.Org xwayland before 24.1.15 and X server before 21.1.26 could be used by authenticated clients to crash or execute code in the X server.

---

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