Telenia Software TVox 26.5.3 and prior 26.x versions, and 24.9.21 and prior 24.x versions, contain an authentication bypass vulnerability in set_env.php where the redirectToLoginAdminIRequestHaveAccessToken() function derives the current page name from PHP_SELF and skips authentication when the value matches 'login_admin.php'. Attackers can append '/login_admin.php' to the path of any target PHP script to cause the authentication check to pass and gain unauthenticated access to all PHP scripts under the manager HTML directory.