Wagtail: Improper permission handling when deleting form submissions

Wagtail is an open source content management system built on Django. Prior to 7.0.7, 7.3.2, and 7.4, a CMS user with limited access to form pages could delete submissions to form pages they don't have access to by crafting a form submission to delete submissions on a page they do have access to for submissions they don't. The vulnerability is not exploitable by an ordinary site visitor without access to the Wagtail admin. This vulnerability is fixed in 7.0.7, 7.3.2, and 7.4.