Wagtail: Improper permission handling in image preview

Wagtail is an open source content management system built on Django. In versions prior to 7.0.8, 7.3.3 and 7.4.2, due to a missing permission check on the image preview endpoint, a user with access to the Wagtail admin can preview any image. The existing data of the image object itself is not exposed. The vulnerability is not exploitable by an ordinary site visitor without access to the Wagtail admin. This issue has been fixed in versions 7.0.8, 7.3.3, and 7.4.2.