Use After Free in X.org Xorg-X11-Server
CVE-2026-56000
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.
Vulnerability class: Use-After-Free
EPSS: 0.002 (13.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Affected products
- X.org Xorg-x11-server — versions 0
- X.org X_server
- X.org Xwayland — versions 0
Weakness classification (CWE)
References
- meissner@suse.de (Patch, patch)
- meissner@suse.de (vendor-advisory, Patch, Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-56000?
- CVE-2026-56000 is a high-severity vulnerability in X.org Xorg-X11-Server, classified under Use After Free. CVSS score: 7.8/10. Published 2026-07-08.
- How severe is CVE-2026-56000?
- High severity. CVSS v3 base score is 7.8 out of 10.