Description
A flaw was found in the X.Org X server. This vulnerability, an out-of-bounds read, affects the XKB (X Keyboard Extension) modifier map handling. An attacker with access to the X11 server can exploit this by sending a malformed request, which causes the server to read beyond its intended memory boundaries. This can lead to the exposure of sensitive information or cause the server to crash, resulting in a denial of service.
Problem types
Buffer Access with Incorrect Length Value
Product status
Timeline
| 2026-03-25: | Reported to Red Hat. |
| 2026-05-05: | Made public. |
Credits
Red Hat would like to thank Jan-Niklas Sohn (TrendAI Zero Day Initiative) for reporting this issue.
References
access.redhat.com/security/cve/CVE-2026-34002
bugzilla.redhat.com/show_bug.cgi?id=2451112 (RHBZ#2451112)