Java 8 Update 73, Java 7 Update 97, and Java 6 Update 113 were announced yesterday by Oracle. The new versions fix a serious vulnerability in the Windows installer for all previous versions of Java.
Although technically you don’t need to install the latest versions of Java if you were already up to date, you should at least make sure that you have uninstalled any older versions of Java on your Windows computers. Also, if you have any previously-downloaded Java installers, you should remove those as well.
And finally, be very careful about where you obtain Java. Always make sure that you’re getting it from Oracle, via the main Java download page or using the Windows Java Control Panel.
A security alert for the new Java versions provides additional information.