Detections
Analytics
CVE-2026-50259
high
Description
A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256] indexed by key type index. The helper function CheckKeyTypes() writes to this buffer at a client-controlled offset, allowing a stack buffer overflow. This may be used to crash the server, or for privilege escalation if the X server runs as root.
References
https://redhat.atlassian.net/browse/PSIRTSUPT-16950
https://lists.x.org/archives/xorg-announce/2026-June/003702.html
https://gitlab.freedesktop.org/xorg/xserver/-/commit/867b59b33bee669cb412f1314e47c52eacf6e00b