CVE-2026-50259
7.8
HIGH
CVSS 3.1
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.
How to fix CVE-2026-50259
No fixed version has been published yet. Mitigate by removing the affected package or applying upstream guidance from the references below.
- Debian/xorg-server—no fix listed
- —no fix listed
Is CVE-2026-50259 being exploited?
No exploitation signal available. Neither CISA KEV nor a current EPSS score has been published for CVE-2026-50259.
Affected packages (2)
- from 0
- from 0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |