Tutor LMS < 3.9.13 - Instructor+ Arbitrary Post Overwrite via IDOR

The Tutor LMS WordPress plugin before 3.9.13 does not verify that the requesting user is allowed to edit a target post before overwriting it in one of its content-builder save handlers, authorizing the request only against an unrelated identifier, allowing authenticated users with instructor-level access to overwrite and take over any post or page on the site, including those owned by administrators.