Multiple cross-site scripting (XSS) vulnerabilities in Extreme Messageboard (XMB) 1.8 SP3 and 1.9 beta allow remote attackers to inject arbitrary web script or HTML via the (1) xmbuser parameter to xmb.php (2) folder parameter to u2u.php (3) viewmost replymost or latest parameter to stats.php (4) message or icons parameter to post.php (5) threadlist pagelinks forumlist navigation or (6) forumdisplay parameter to forumdisplay.php.