The LifterLMS WordPress plugin before 10.0.10 does not perform a capability check in one of its select2 query AJAX handlers, only verifying that the user is logged in, allowing any authenticated user with subscriber-level access to read the titles of internal post types such as coupon codes by supplying the post type.
https://wpscan.com/vulnerability/2a353964-9f4c-4528-b187-42766f0cfaed/