phpBB 3.2.8 allows a CSRF attack that can approve pending group memberships.

phpBB 3.2.8 allows a CSRF attack that can modify a group avatar.

The fulltext search component in phpBB before 3.2.6 allows Denial of Service.

In phpBB before 3.1.7-PL1, includes/acp/acp_bbcodes.php has improper verification of a CSRF token on the BBCode page in the Administration Control Panel. An actual CSRF attack is possible if an attacker also manages to retrieve the session id of a reauthenticated administrator prior to targeting them.

phpBB 3.2.7 allows adding an arbitrary Cascading Style Sheets (CSS) token sequence to a page through BBCode.

Missing form token validation in phpBB 3.2.7 allows CSRF in deleting post attachments.

phpBB version 3.2.7 allows the stealing of an Administration Control Panel session id by leveraging CSRF in the Remote Avatar feature. The CSRF Token Hijacking leads to stored XSS

Server side request forgery (SSRF) in phpBB before 3.2.6 allows checking for the existence of files and services on the local network of the host through the remote avatar upload function.

Passing an absolute path to a file_exists check in phpBB before 3.2.4 allows Remote Code Execution through Object Injection by employing Phar deserialization when an attacker has access to the Admin Control Panel with founder permissions.

phpBB version 3.2.0 is vulnerable to SSRF in the Remote Avatar function resulting allowing an attacker to perform port scanning, requesting internal content and potentially attacking such internal services via the web application.

phpbb 3.0.x-3.0.6 has an XSS vulnerability via the [flash] BB tag.