Description
A flaw was found in the X.Org X server. This integer underflow vulnerability, specifically in the XKB compatibility map handling, allows an attacker with local or remote X11 server access to trigger a buffer read overrun. This can lead to memory-safety violations and potentially a denial of service (DoS) or other severe impacts.
References10
- access.redhat.com/errata/RHSA-2026:10739
- access.redhat.com/errata/RHSA-2026:11352
- access.redhat.com/errata/RHSA-2026:11369
- access.redhat.com/errata/RHSA-2026:11388
- access.redhat.com/errata/RHSA-2026:11656
- access.redhat.com/errata/RHSA-2026:11692
- access.redhat.com/errata/RHSA-2026:13414
- access.redhat.com/errata/RHSA-2026:19125
- access.redhat.com/errata/RHSA-2026:19342
- access.redhat.com/errata/RHSA-2026:19343
Metrics
- CVSS 3.1
-
7.8
HIGH
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 33 · as of 13 November 2026
- CWE
- CWE-191
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.