Use After Free Affecting tigervnc package, versions <0:1.8.0-36.el7_9.5


Severity

Recommended
0.0
high
0
10

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.15% (6th percentile)

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  • Snyk IDSNYK-RHEL7-TIGERVNC-18323959
  • published27 Jul 2026
  • disclosed2 Jun 2026

Introduced: 2 Jun 2026

CVE-2026-50261  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade RHEL:7 tigervnc to version 0:1.8.0-36.el7_9.5 or higher.
This issue was patched in RHSA-2026:46473.

NVD Description

Note: Versions mentioned in the description apply only to the upstream tigervnc package and not the tigervnc package as distributed by RHEL. See How to fix? for RHEL:7 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1