“Java is a plugin for web browsers that is installed on approximately 66% of all computers. However there are very few websites that still rely on the features that it provides, leaving those 66% of computers vulnerable to attack when the dated technology is exploited. This has unfortunately happened several times in the past few months.” — Examples of why you should disable Java
Windows PCs and Macs are equally at risk. The JDK7 version of the software is affected but it does not affect Java applications directly installed and running on servers, desktops, laptops and other devices.
Please note that this exploit refers to is regarding the Java browser plug-in. Stand alone programs written in Java (such as those packaged as .jar files) are okay, of course, considering you get them from trustworthy sources.
If you have the Java browser plugin and use any of these browsers, Chrome, Firefox, Internet Explorer, Opera and Safari then your computer is vulnerable. Oracle says fix will be available shortly but in the meantime here are is the answer to the question- How to disable Java in my web browser?
Instructions for disabling Java in the major browsers were first found on the US-CERT (United States Computer Emergency Readiness Team) website.