What is CVE-2026-93523?

CVE-2026-93523 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-2026-93523?

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

Buffer overflow in X.org Xorg-X11-Server

CVE-2026-93523

A heap buffer overflow caused by a XIPassiveUngrabDevice request with an out-of-range modifier value in X.Org X Server before 21.1.15 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.

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/37a1847a60c6799aecf163a5cfa40077a9… (patch)

Frequently asked questions

What is CVE-2026-93523?: CVE-2026-93523 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-2026-93523?: High severity. CVSS v3 base score is 7.8 out of 10.