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.
https://exchange.xforce.ibmcloud.com/vulnerabilities/34947
http://www.dragoslungu.com/2007/06/07/bbpress-xss-vulnerability/