Cross-site scripting (XSS) vulnerability in the remote RSS sidebar plugin (serendipity_plugin_remoterss) in S9Y Serendipity before 1.2.1 allows remote attackers to inject arbitrary web script or HTML via a link in an RSS feed.
Cross-site request forgery (CSRF) vulnerability in the Entry Manager in Serendipity before 1.0-beta3 allows remote attackers to perform unauthorized actions as a logged-in user via a link or IMG tag.