WWBN AVideo is an open source video platform. In 29.0 and earlier, objects/mention.json.php has no User::loginCheck() or admin gate. It only has an entry guard: preg_match('/^@/', $_REQUEST['term']) and hard-coded rowCount=10. This enables unauthenticated user enumeration.
Exploitability
AV:NAC:LPR:NUI:NScope
S:UImpact
C:LI:NA:N5.3/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N