CVEvulnerability

CVE-2026-50258

7.8 HIGH Published 2026-06-05 Modified 2026-08-05 Official page ↗
Status
Modified
Published
2026-06-05
Last modified
2026-08-05
Assigner
[email protected]
CVSS 3.1 ([email protected])
7.8 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 3.1 (0b0ca135-0b70-47e7-9f44-1890c2a1c46c)
7.8 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weaknesses
CWE-121

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.

Affected configurations

• x.org x server (< 21.1.23) • x.org xwayland (< 24.1.12) • redhat enterprise linux 7.0 • redhat enterprise linux 8.0 • redhat enterprise linux 9.0 • redhat enterprise linux 10.0

Related

Weakness · CWE (1)

  • CWE-121 Stack-based Buffer Overflow weakness

References