NetSight
IP …
high7.8

CVE-2026-50257

A use-after-free flaw was found in the X.Org X server and Xwayland in miSyncDestroyFence().

Impact

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.

Affected products

VendorProductAffected versions
X.OrgX Server
before 21.1.23
X.OrgXwayland
before 24.1.12
RedhatEnterprise Linux
Versions 7.0, 8.0, 9.0, 10.0

Weakness classification

CWE-416

References