Mozilla Firefox 3.x before 3.0.5 and 2.x before 2.0.0.19, Thunderbird 2.x before 2.0.0.19, and SeaMonkey 1.x before 1.1.14 allows remote attackers to bypass the same origin policy and conduct cross-site scripting (XSS) attacks via an XBL binding to an "unloaded document."