CyberRota Analysis
This is a high severity vulnerability with a CVSS score of 7.8. See the original NVD description below for full technical details.
CVE
CVE-2026-50258
Severity
HIGH
CVSS
7.8
EPSS
0.16%
Original NVD Description
A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. The X server has multiple stack buffers sized XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify or clamp non-canonical key types to XkbMaxShiftLevel. A client can change key types to excessive shift levels and trigger stack overflows. This is caused by an incomplete fix of CVE-2025-26597. This may be used to crash the server, or for privilege escalation if the X server runs as root.
Related CVEs
Other vulnerabilities affecting the same vendor(s)