CyberRota Analysis
This is a high severity vulnerability with a CVSS score of 7.8. See the original NVD description below for full technical details.
CVE
CVE-2026-50257
Severity
HIGH
CVSS
7.8
EPSS
0.14%
Original NVD Description
A use-after-free flaw was found in the X.Org X server and Xwayland in miSyncDestroyFence(). A client that sets up multiple fence triggers can trigger a use-after-free function pointer call. An attacker would connect to the X server to set up a fence and await that fence, then a second X connection destroys the fence, causing the use-after-free. This may be used to crash the server, or for privilege escalation if the X server runs as root.
Related CVEs
Other vulnerabilities affecting the same vendor(s)