CVE-2026-50260

Published Jun 5, 2026

Last updated 2 days ago

Overview

AI description

Automated description summarized from trusted sources.

CVE-2026-50260 describes a use-after-free vulnerability identified within the `FreeCounter()` function of the X.Org X server and Xwayland. This flaw can be triggered when a client establishes multiple SyncCounters and awaits their triggers. A second client connection can then destroy these counters, leading to a use-after-free condition. Exploiting this vulnerability could result in the server crashing or, if the X server is running with root privileges, could lead to privilege escalation. The issue was reported by Anonymous from Trend Micro Zero Day Initiative.

Description
A use-after-free flaw was found in the X.Org X server and Xwayland in FreeCounter(). A client that sets up multiple SyncCounters and awaits on those triggers can trigger a use-after-free when destroying those counters via a second client connection. 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

5