Cross-site scripting (XSS) vulnerability in printthread.php in MyBB 1.0.1 and earlier allows remote attackers to inject arbitrary web script or HTML via a thread message, which is not properly sanitized in the print view of the thread.
http://www.vupen.com/english/advisories/2006/0012
http://www.securityfocus.com/bid/16096
http://www.securityfocus.com/archive/1/420569/100/0/threaded