cvedb.io
CVE-2026-50257
HIGH · CVSS 7.8
EPSS exploitation probability: 3%
Published 2026-06-05T12:16:38.907 · Last modified 2026-06-24T11:16:35.033

Summary

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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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.