Description
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-bounds memory. An attacker with a connection to the X11 server, either locally or remotely, can exploit this without user interaction. This could lead to the disclosure of memory contents or cause a denial of service by crashing the server.
Affected products
x.org: x server; redhat: enterprise linux
References10
- access.redhat.com/errata/RHSA-2026:19342
- access.redhat.com/errata/RHSA-2026:20547
- access.redhat.com/errata/RHSA-2026:20555
- access.redhat.com/errata/RHSA-2026:20557
- access.redhat.com/errata/RHSA-2026:20558
- access.redhat.com/errata/RHSA-2026:20560
- access.redhat.com/errata/RHSA-2026:20561
- access.redhat.com/errata/RHSA-2026:20562
- access.redhat.com/errata/RHSA-2026:20563
- access.redhat.com/errata/RHSA-2026:20575
Metrics
- CVSS 3.1
-
9.1
CRITICAL
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H - EPSS — exploit probability
- 0% percentile: 43 · as of 13 November 2026
- CWE
- CWE-125
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.