WebKit in Apple Mac OS X 10.3.9 and 10.4.7 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted HTML document that causes WebKit to access an object that has already been deallocated.
lists.apple.com/archives/security-announce/2006//Aug/msg00000.html
secunia.com/advisories/21253
www.kb.cert.org/vuls/id/566132
www.osvdb.org/27744
www.securityfocus.com/bid/19289
www.us-cert.gov/cas/techalerts/TA06-214A.html
www.vupen.com/english/advisories/2006/3101
exchange.xforce.ibmcloud.com/vulnerabilities/28149