You will sometimes run into this issue when using CakePHP, I did  a few times, and randomly or so it seemed and the reason is in my case, and I want to bet in most cases, is that you are using the Auth Component, and added a new action to your controller, and simply forgot to add it to the allowed functions in the Auth Component. Make sure you add the action name that you want to be made available to anyone to the Auth.allow() call in your beforeFilter() function body in the controller where the action is defined.