FearlessCMS is a flat-file content management system centered on simplicity and open source. Prior to version 0.1.4, five debug/test PHP scripts under admin/ perform privileged operations without isLoggedIn() authentication checks, CSRF protection or adequate path validation. On PHP's built-in development server, including the default Docker deployment, router.php checks an unnormalized admin URI prefix while the filesystem resolves dot segments, so /./admin/ bypasses the admin login gate and executes those scripts directly. In admin/debug_save_flow.php, attacker-controlled path and content reach file_put_contents for arbitrary .md writes under content/ or outside it through path traversal, enabling site defacement and stored JavaScript in public pages; print_r($_POST) output without…