Use-after-free vulnerability in WebKit in Apple Safari before 4.0.5 allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via an HTML document with improperly nested tags.
https://exchange.xforce.ibmcloud.com/vulnerabilities/56836
http://www.ubuntu.com/usn/USN-1006-1
http://support.apple.com/kb/HT4225
http://support.apple.com/kb/HT4070
http://lists.opensuse.org/opensuse-security-announce/2011-01/msg00006.html
http://lists.fedoraproject.org/pipermail/package-announce/2010-May/041436.html
http://lists.fedoraproject.org/pipermail/package-announce/2010-May/041432.html
http://lists.fedoraproject.org/pipermail/package-announce/2010-May/041383.html
http://lists.apple.com/archives/security-announce/2010/Mar/msg00000.html
http://lists.apple.com/archives/security-announce/2010/Jun/msg00003.html