The User Profile Picture plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 2.6.1 via the 'rest_api_change_profile_image' function due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with Author-level access and above, to update the profile picture of any user.

The User Profile Picture WordPress plugin before 2.6.0 was affected by an IDOR issue, allowing users with the upload_image capability (by default author and above) to change and delete the profile pictures of other users (including those with higher roles).

The REST API endpoint get_users in the User Profile Picture WordPress plugin before 2.5.0 returned more information than was required for its functionality to users with the upload_files capability. This included password hashes, hashed user activation keys, usernames, emails, and other less sensitive information.