CVE 2012-0446
Multiple cross-site scripting (XSS) vulnerabilities in Mozilla Firefox 4.x through 9.0, Thunderbird 5.0 through 9.0, and SeaMonkey before 2.7 allow remote attackers to inject arbitrary web script or HTML via a (1) web page or (2) Firefox extension, related to improper enforcement of XPConnect security restrictions for frame scripts that call untrusted objects.
See the 
CVE page on Mitre.org
for more details.
