The PMPageFormatCreateWithDataRepresentation API in Printing in Apple Mac OS X 10.5.8 and 10.6.x before 10.6.5 does not properly handle XML data, which allows attackers to cause a denial of service (NULL pointer dereference and application crash) via unspecified API calls.
http://www.securitytracker.com/id?1024723
http://support.apple.com/kb/HT4435
http://lists.apple.com/archives/security-announce/2010//Nov/msg00000.html