This feature release does not contain any new fixes for security vulnerabilities to its previous release, Java SE 6 Update 17. Users who have Java SE 6 Update 17 have the latest security fixes and do not need to upgrade to this release to be current on security fixes.

Site/Download:
http://java.sun.com/javase/downloads/index.jsp

Bug fixes:
http://java.sun.com/javase/6/webnotes/6u18.html#bugfixes-1.6.0_18