---
id: "CVE-2026-93516"
kind: "vulnerability"
aliases: ["CVE-2026-93516"]
title: "X.org X Server: use-after-free when adding or removing XInput master devices"
severity: "medium"
cvss: 5.5
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["desktop", "infrastructure", "linux", "multi-user", "xorg", "xwayland"]
not_affected_if: ["no-untrusted-x-clients", "wayland-only-no-xwayland"]
published_at: "2026-10-28T13:17:29+00:00"
first_seen_at: "2026-10-28T13:33:01+00:00"
updated_at: "2026-10-28T13:34:26+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-93516", "first_seen_at": "2026-10-28T13:33:01+00:00"}]
---

# X.org X Server: use-after-free when adding or removing XInput master devices

X.org X Server and XWayland mishandle the lifetime of XInput master devices when they are added or removed, leaving a use-after-free. An authenticated X client can crash the X server or potentially execute code in the X server's context.

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

## How to check

- Run `Xorg -version` or `X -version` and compare against `21.1.25`
- Run `Xwayland -version` and compare against `24.1.14`
- Check your distribution's package manager for the installed xorg-server or xwayland package version

## Fix

- Upgrade X.org X Server to `21.1.25` or later
- Upgrade XWayland to `24.1.14` or later
- Apply your distribution's xorg-server and xwayland security updates

## Timeline

- 2026-10-28T13:33:01+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-93516

## From the sources

A use-after-free caused by lack of lifecycle management when adding / removing XInput master devices in X.org X Server before 21.1.25 and XWayland before 24.1.14 could be used by authenticated X Clients to crash the X server or potentially execute code in X server context.

---

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