CVE-2026-50261

Published Jun 5, 2026

Last updated 2 days ago

Overview

AI description

Automated description summarized from trusted sources.

CVE-2026-50261 describes a use-after-free vulnerability found in the `SyncChangeCounter()` function of the X.Org X server and Xwayland. This flaw can be exploited by a client that establishes multiple `SyncCounters` and subsequently destroys them through a separate client connection while these counters are in the process of being modified. The successful exploitation of this vulnerability could lead to a server crash. Additionally, if the X server is operating with root privileges, it could potentially result in privilege escalation.

Description
A use-after-free flaw was found in the X.Org X server and Xwayland in SyncChangeCounter(). A client that sets up multiple SyncCounters can trigger a use-after-free when destroying those counters via a second client connection while changing those counters. This may be used to crash the server, or for privilege escalation if the X server runs as root.
Source
secalert@redhat.com
NVD status
Undergoing Analysis

Risk scores

CVSS 3.1

Type
Primary
Base score
7.8
Impact score
5.9
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity
HIGH

Weaknesses

secalert@redhat.com
CWE-416

Social media

Hype score is a measure of social media activity compared against trending CVEs from the past 12 months. Max score 100.

Hype score

3