Wagtail is an open source content management system built on Django. A user with a limited-permission editor account for the Wagtail admin can make a direct URL request to the admin view that handles bulk actions on user accounts. While authentication rules prevent the user from making any changes, the error message discloses the display names of user accounts, and by modifying URL parameters, the user can retrieve the display name for any user. The vulnerability is not exploitable by an ordinar