Multiple cross-site scripting (XSS) vulnerabilities in templates/2k11/admin/overview.inc.tpl in Serendipity before 2.0-rc2 allow remote attackers to inject arbitrary web script or HTML via a blog comment in the QUERY_STRING to serendipity/index.php.
https://github.com/s9y/Serendipity/commit/36cde3030aaa27a46bf94086e062dfe56b60230b
https://exchange.xforce.ibmcloud.com/vulnerabilities/99464
http://www.securityfocus.com/archive/1/534315/100/0/threaded
http://blog.s9y.org/archives/259-Serendipity-2.0-rc2-released.html