---
id: CVE-2026-50263
title: >-
  A use-after-free flaw was found in the X.Org X server and Xwayland in
  CreateSaverWindow()
summary: >-
  A use-after-free flaw was found in the X.Org X server and Xwayland in
  CreateSaverWindow(). A client can trigger a use-after-free read after changing
  window attributes and forcing the screen saver, leading to information
  disclosure.
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-416
vendor: x.org
product: x_server
affected:
  - x_server < 21.1.23
  - xwayland < 24.1.12
  - enterprise_linux = 7.0
  - enterprise_linux = 8.0
  - enterprise_linux = 9.0
  - enterprise_linux = 10.0
patched:
  - x_server 21.1.23
  - xwayland 24.1.12
published: '2026-06-05'
updated: '2026-07-07'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-50263'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2026:26562'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:26566'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:26590'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:26610'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:26709'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:28923'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:29844'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:36086'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/security/cve/CVE-2026-50263'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2485388'
    label: secalert@redhat.com
  - url: >-
      https://gitlab.freedesktop.org/xorg/xserver/-/commit/ecc634f1b2f7aa473d3a267eada98c4918bf9e05
    label: secalert@redhat.com
  - url: 'https://lists.x.org/archives/xorg-announce/2026-June/003702.html'
    label: secalert@redhat.com
  - url: 'https://redhat.atlassian.net/browse/PSIRTSUPT-16950'
    label: secalert@redhat.com
tags:
  - nvd
epss: 0.00188
epssPercentile: 0.07382
ingestedAt: '2026-07-07T08:52:24.953Z'
---

## Overview

A use-after-free flaw was found in the X.Org X server and Xwayland in CreateSaverWindow(). A client can trigger a use-after-free read after changing window attributes and forcing the screen saver, leading to information disclosure.

## Affected

- `x_server < 21.1.23`
- `xwayland < 24.1.12`
- `enterprise_linux = 7.0`
- `enterprise_linux = 8.0`
- `enterprise_linux = 9.0`
- `enterprise_linux = 10.0`

## Remediation

Upgrade past the affected range:

- `x_server 21.1.23`
- `xwayland 24.1.12`