Out-of-bounds Read in X.org X_server

CVE-2026-34000

A flaw was found in the X.Org X server. This out-of-bounds read vulnerability in the XKB geometry processing, specifically within the `CheckSetGeom()` and `XkbAddGeomKeyAlias` functions, allows an attacker to read uninitialized or out-of-b…

Vulnerability class: Buffer Overflow

EPSS: 0.000 (9.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-34000?
CVE-2026-34000 is a medium-severity vulnerability in X.org X_server, classified under Out-of-bounds Read. CVSS score: 6.1/10. Published 2026-05-05.
How severe is CVE-2026-34000?
Medium severity. CVSS v3 base score is 6.1 out of 10.