What is CVE-2026-88806?

CVE-2026-88806 is a high-severity vulnerability in X.org Libx11, classified under Heap-based Buffer Overflow. CVSS score: 7.5/10. Published 2026-09-21.

How severe is CVE-2026-88806?

High severity. CVSS v3 base score is 7.5 out of 10.

Buffer overflow in X.org Libx11

CVE-2026-88806

A malicious X server could exploit a buffer overflow in libX11 before 1.8.14 during handling of XkbGetMap overflowing the key_sym_map.

Vulnerability class: Buffer Overflow

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

X.org Libx11

Weakness classification (CWE)

CWE-122 — Heap-based Buffer Overflow

References

meissner@suse.de (patch)

Frequently asked questions

What is CVE-2026-88806?: CVE-2026-88806 is a high-severity vulnerability in X.org Libx11, classified under Heap-based Buffer Overflow. CVSS score: 7.5/10. Published 2026-09-21.
How severe is CVE-2026-88806?: High severity. CVSS v3 base score is 7.5 out of 10.