Multiple cross-site scripting (XSS) vulnerabilities in the JoomlaSeller JS Calendar (com_jscalendar) component 1.5.1 and 1.5.4 for Joomla! allow remote attackers to inject arbitrary web script or HTML via the (1) month and (2) year parameters in a jscalendar action to index.php.  NOTE: some of these details are obtained from third party information.