CVE 2010-2753
Integer overflow in Mozilla Firefox 3.5.x before 3.5.11 and 3.6.x before 3.6.7, Thunderbird 3.0.x before 3.0.6 and 3.1.x before 3.1.1, and SeaMonkey before 2.0.6 allows remote attackers to execute arbitrary code via a large selection attribute in a XUL tree element, which triggers a use-after-free.
See the 
CVE page on Mitre.org
for more details.
