Unspecified versions of Mozilla Firefox allow remote attackers to cause a denial of service (crash) via a web page that contains a large number of nested marquee tags. NOTE: a followup post indicated that the initial report could not be verified.
https://exchange.xforce.ibmcloud.com/vulnerabilities/26898
http://www.securityfocus.com/archive/1/436268/100/0/threaded
http://www.securityfocus.com/archive/1/435882/100/0/threaded
http://www.securityfocus.com/archive/1/435411/100/0/threaded
http://www.securityfocus.com/archive/1/435373/100/0/threaded