CVE-2026-93521

A flaw was found in xorg-x11-server. The X server incorrectly calculates buffer sizes and memory offsets when prepending or appending data to RandR (Resize and Rotate extension) provider properties. A local attacker can exploit this vulnerability by sending specially crafted property update requests, causing memory corruption. This flaw could allow an attacker to escalate privileges or cause a denial of service (DoS) by crashing the X server.

This vulnerability is rated as an Important severity flaw because an authenticated local client can trigger memory corruption within the X server to crash the display server or potentially execute arbitrary code with elevated privileges. In Red Hat Enterprise Linux environments, modern desktop sessions default to Wayland, which restricts direct exposure to Xwayland compatibility instances. However, systems actively utilizing traditional Xorg sessions remain exposed to local privilege escalation by any authorized user with access to the X display.

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.