CVE-2026-50258

CVE-2026-50258

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 XkbMa…

Vulnerability class: Buffer Overflow

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-50258?
CVE-2026-50258 is a high-severity vulnerability, classified under Stack-based Buffer Overflow. CVSS score: 7.8/10. Published 2026-06-05.
How severe is CVE-2026-50258?
High severity. CVSS v3 base score is 7.8 out of 10.