The plug-in interface in WebKit in Apple Safari before 3.2 does not prevent plug-ins from accessing local URLs, which allows remote attackers to obtain sensitive information via vectors that "launch local files."
Apple Safari 2.0.3 (417.9.3) on Mac OS X 10.4.6 allows remote attackers to cause a denial of service (CPU consumption) via Javascript with an infinite for loop. NOTE: it could be argued that this is not a vulnerability, unless it interferes with the operation of the system outside of the scope of Safari itself.