Claude Code — Vulnerability (CVE-2026-35603)
Date: 2026-04
Affected: anthropic/claude_code, microsoft/windows
Attack vector: other
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2026-35603
CWE: CWE-426
CVSS: 7.3 (CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H)

Claude Code is an agentic coding tool. In versions prior to 2.1.75 on Windows, Claude Code loaded the system-wide default configuration from C:\ProgramData\ClaudeCode\managed-settings.json without validating directory ownership or access permissions. Because the ProgramData directory is writable by non-administrative users by default and the ClaudeCode subdirectory was not pre-created or access-restricted, a low-privileged local user could create this directory and place a malicious configuration file that would be automatically loaded for any user launching Claude Code on the same machine. Exploiting this would have required a shared multi-user Windows system and a victim user to launch Claude Code after the malicious configuration was placed. This issue has been fixed on version 2.1.75.


Mitigations:

Architectural layers (MAESTRO):