Release notes:
http://java.sun.com/javase/6/webnotes/6u11.html

-18- bug fixes...
"This release contains fixes for one or more security vulnerabilities. For more information, please see Sun Alerts 244986, 244987, 244988, 244989, 244990, 244991, 244992, 245246, 246266, 246286, 246346, 246366, and 246387..."

Java version test:
http://javatester.org/version.html