vBulletin 5.x through 5.1.6 allows remote authenticated users to bypass authorization checks and inject private messages into conversations via vectors related to an input validation failure.

Cross-site scripting (XSS) vulnerability in vBulletin 3.5.4, 3.6.0, 3.6.7, 3.8.7, 4.2.2, 5.0.5, and 5.1.3.

The vB_Api_Hook::decodeArguments method in vBulletin 5 Connect 5.1.2 through 5.1.9 allows remote attackers to conduct PHP object injection attacks and execute arbitrary PHP code via a crafted serialized object in the arguments parameter to ajax/api/hook/decodeArguments.

SQL injection vulnerability in vBulletin 5.0.4 through 5.1.3 Alpha 5 allows remote attackers to execute arbitrary SQL commands via the criteria[startswith] parameter to ajax/render/memberlist_items.