The bbPress plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2.6.11. This is due to missing or incorrect nonce validation on the bbpuseraddroleonregister() function. This makes it possible for unauthenticated attackers to elevate their privileges to that of a bbPress Keymaster via a forged request granted they can trick a site administrator into performing an action such as clicking on a link. Rather than implementing a nonce check to provide protection against this vulnerability, which would break functionality, the plugin no longer makes it possible to select a role during registration.

bbPress 1.0.2 allows remote attackers to obtain sensitive information via a direct request to a .php file, which reveals the installation path in an error message, as demonstrated by bb-templates/kakumei/view.php and certain other files.

SQL injection vulnerability in bb-includes/formatting-functions.php in bbPress before 0.8.1 might allow remote attackers to execute arbitrary SQL commands via unspecified vectors to forums/bb-edit.php, as demonstrated by a PRE element, aka the "quircky slashes bug."

Cross-site scripting (XSS) vulnerability in bb-login.php in bbPress 0.8.1 allows remote attackers to inject arbitrary web script or HTML via the re parameter. NOTE: exploitation may require forcing the client to send a certain Referer header.