PT-2026-46937 · X.Org Foundation+1 · Xwayland+2
CVE-2026-50257
·
Published
2026-04-20
·
Updated
2026-07-13
CVSS v3.1
7.8
High
| Vector | AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Name of the Vulnerable Software and Affected Versions
X.Org X server (affected versions not specified)
Xwayland (affected versions not specified)
Description
A use-after-free flaw exists in the
miSyncDestroyFence() function. This occurs when a client sets up multiple fence triggers, allowing a function pointer call to access memory after it has been freed. An attacker can exploit this by connecting to the X server to set up and await a fence, while a second X connection destroys that fence. This can lead to a server crash or privilege escalation if the X server is running with root privileges.Recommendations
At the moment, there is no information about a newer version that contains a fix for this vulnerability.
Exploit
LPE
DoS
Use After Free
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Weakness Enumeration
Related Identifiers
Affected Products
Rocky Linux
X.Org Server
Xwayland