Copyright © 2012 Red Hat, Inc. All rights reserved. Important 2026-07-08T00:00:00 X.org: xorg-x11-server: GLX contextTags Use-After-Free in CommonMakeCurrent() 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CWE-825

Local attackers with a X connection able to provide GLX commit to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a Heap Use After Free, due to CommonMakeCurrent() pointing into potentially reallocated memory.

A flaw was found in the X.org X11 server, specifically within the GLX (OpenGL Extension to the X Window System) dispatch layer. A remote attacker can exploit this vulnerability by sending a series of crafted X11 requests. This can lead to a use-after-free condition, where the server attempts to write data to memory that has already been released. The primary consequence of this memory corruption is a denial of service, potentially causing the X server to crash.

An Important use-after-free vulnerability in the X.org X11 server's GLX dispatch layer allows a remote, unauthenticated attacker to trigger a denial of service. By sending a sequence of crafted X11 requests, an attacker can cause the X server to crash, impacting the availability of systems with a running graphical environment. This is considered Important due to the remote attack vector and the potential for unauthenticated denial of service. Red Hat Enterprise Linux 10 2026-07-13T00:00:00Z RHSA-2026:38489 xorg-x11-server-Xwayland-0:24.1.9-4.el10_2.3 Red Hat Enterprise Linux 9 2026-07-13T00:00:00Z RHSA-2026:38490 xorg-x11-server-Xwayland-0:24.1.9-4.el9_8.3 Red Hat Enterprise Linux 6 Not affected xorg-x11-server Red Hat Enterprise Linux 7 Not affected xorg-x11-server Red Hat Enterprise Linux 8 Affected xorg-x11-server Red Hat Enterprise Linux 8 Affected xorg-x11-server-Xwayland Red Hat Enterprise Linux 9 Affected xorg-x11-server https://www.cve.org/CVERecord?id=CVE-2026-56000 https://nvd.nist.gov/vuln/detail/CVE-2026-56000