Wimi Teamwork On-Premises < 8.2.0 IDOR via preview.php

Wimi Teamwork On-Premises versions prior to 8.2.0 contain an insecure direct object reference vulnerability in the preview.php endpoint where the item_id parameter lacks proper authorization checks. Attackers can enumerate sequential item_id values to access and retrieve image previews from other users' private or group conversations, resulting in unauthorized disclosure of sensitive information.