CVE-2026-50260

HighCVSS 7.8

Published: 05/06/2026(UTC)Updated: 09/07/2026(UTC)Translated: 10/07/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.15%

5th percentile - higher than 5% of all known CVEs

Summary

A use-after-free vulnerability was found in the X.Org X server and Xwayland in the FreeCounter() function. 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.

Risk Assessment

This vulnerability may cause the X server to crash or lead to privilege escalation if the X server runs as root, posing a serious risk to system stability and security.

Recommendation

Immediately update the X.Org X server and Xwayland packages to a patched version. If an update is not possible, restrict access to the X server to trusted users only.

Original NVD description (English source)

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.