PT-2026-56335 · X.Org · Xorg-X11-Server+1

Published 2026-07-08 · Updated 2026-07-08 · CVE-2026-56000

NVD

CVSS v4.0

9.0

Critical

Base vector

AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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.

Fix

Use After Free

Weakness Enumeration

CWE-416

Related Identifiers

CVE-2026-56000

Affected Products

Xorg-X11-Server

Xwayland

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-56000 · Security Note
• https://gitlab.freedesktop.org/xorg/xserver/-/commit/2779affbdb4354e894f490e56f962527d6125043 · Patch
• https://openwall.com/lists/oss-security/2026/07/08/2 · Vendor Advisory