Cross-site scripting (XSS) vulnerability in the sidebar HTML page in the MouseoverDictionary before 0.6.2 extension for Mozilla Firefox allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.
https://exchange.xforce.ibmcloud.com/vulnerabilities/37184
http://www.securityfocus.com/bid/26053
http://secunia.com/advisories/27195