Use After Free Affecting xorg-server package, versions [,21.1.23)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-UNMANAGED-XORGSERVER-17308631
- published11 Jun 2026
- disclosed2 Jun 2026
- creditUnknown
Introduced: 2 Jun 2026
CVE-2026-50257 (opens in a new tab)How to fix?
Upgrade xorg-server to version 21.1.23 or higher.
Overview
Affected versions of this package are vulnerable to Use After Free via the miSyncDestroyFence() function. An attacker can execute arbitrary code or cause a server crash by establishing multiple connections to set up and destroy a fence, leading to a use-after-free condition when a function pointer is called after the fence is destroyed. This may result in privilege escalation if the server is running with elevated privileges.