CVE-2026-50263

A use-after-free flaw was found in the X.Org X server and Xwayland in CreateSaverWindow(). A client can trigger a use-after-free read after changing window attributes and forcing the screen saver, leading to information disclosure.

Red Hat rates this issue as Moderate impact. In xorg-x11-server and xorg-x11-server-Xwayland, a local X client can trigger a use-after-free read in CreateSaverWindow() by changing window attributes and forcing the screen saver, leaking server memory to the client. Any local user who can connect to the X server display can attempt exploitation. Upstream fixed this in xorg-server 21.1.23 and xwayland 24.1.12.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.