What is CVE-2026-93520?

CVE-2026-93520 is a high-severity vulnerability in X.org Xorg-X11-Server, classified under Heap-based Buffer Overflow. CVSS score: 7.8/10. Published 2026-10-28.

How severe is CVE-2026-93520?

High severity. CVSS v3 base score is 7.8 out of 10.

Buffer overflow in X.org Xorg-X11-Server

CVE-2026-93520

A heap buffer overflow caused by mismatching size calculations between XkbAllocNames and ChangeKeycodeRange in X.org X server before 2.1.25 and XWayland before 24.1.14 could be used by authenticated X clients to crash or potentially execute code in X server context.

Vulnerability class: Buffer Overflow

Published 2026-10-28 · last modified 2026-10-28.

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.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

CWE-122 — Heap-based Buffer Overflow

References

gitlab.freedesktop.org/xorg/xserver/-/commit/b941a473e06f26a407a9adb15759be79f7… (patch)

Frequently asked questions

What is CVE-2026-93520?: CVE-2026-93520 is a high-severity vulnerability in X.org Xorg-X11-Server, classified under Heap-based Buffer Overflow. CVSS score: 7.8/10. Published 2026-10-28.
How severe is CVE-2026-93520?: High severity. CVSS v3 base score is 7.8 out of 10.