CVE-2026-50258

Published: Giu 05, 2026 Last Modified: Giu 05, 2026

ExploitDB:

Other exploit source:

Google Dorks:

HIGH 7,8

Source: [email protected]

Attack Vector: local

Attack Complexity: low

Privileges Required: low

User Interaction: none

Scope: unchanged

Confidentiality: high

Integrity: high

Availability: high

Description

AI Translation Available

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.

121

Stack-based Buffer Overflow

Draft

Abstraction: Variant Structure: Simple

Common Consequences

Security Scopes Affected:

Availability Integrity Confidentiality Access Control Other

Potential Impacts:

Modify Memory Dos: Crash, Exit, Or Restart Dos: Resource Consumption (Cpu) Dos: Resource Consumption (Memory) Execute Unauthorized Code Or Commands Bypass Protection Mechanism Other