CVE-2026-93515

A flaw was found in xorg-x11-server. A use-after-free vulnerability, where the application accesses memory after it has already been released, occurs in the Present extension because window notification entries are not properly unlinked before cleaning up window resources. An authenticated local X client can exploit this flaw by creating cross-window notifications and subsequently destroying the target window. Successful exploitation primarily results in a Denial of Service (DoS) via an X server crash, and may potentially lead to information disclosure.

This vulnerability is rated as a Moderate impact for Red Hat Enterprise Linux because exploitation requires an established, authenticated local client connection to the display server, preventing unauthenticated remote exploitation. In environments running the X server or Xwayland, a client within an active graphical session can trigger memory corruption by manipulating presentation event notifications across terminating application windows. The primary impact is a display server crash that terminates active user sessions, though limited local information disclosure may also occur.

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.