Vulnerability in EPiServer.Forms
We are using attributes on content areas to restrict the number of items an editor can add to the content area. This works very well, however the editor is only aware that they aren't permitted to add more than X items into the content area only when they click 'Create' on the item.
We would like funtionality which restricts the user before they create the item. For example, if the user clicks the 'create a new block' link in a content area which contains the max number of items already, then the editor should be notified that the action is not possible.
Please have a look in that blog post. I think it will help you to resolve your issue.