CVE-2026-50257 | BDVDB-2026-338312 Detail

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.

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Exploit#

History#

1. Version 12026-06-05Record published in the CVE List.
2. Version 22026-11-04Most recent update recorded in the CVE List.