The serious security issues present in Java RunTime Environment (JRE) is one of the reason why you must turn off Java plugin on your browser. As reported by The Register, Java version 1.7 or higher installed on your PCs can cause problems.
Attackers can use custom webpage to force your Mac or Windows computer to download programs like Keylogger or malwares. That’s downright scary, so all the browsers running Java 1.7 should either remove the Java plugin completely or disable it temporarily from their browser — be it Mozilla Firefox, Google Chrome, Safari, Opera, or Microsoft’s Internet Explorer.
Removing Java plugin will stop your browser from running Java applets on websites. But once you learn the technique of disabling Java plugin on your computer (it’s really easy), you can always enable it again to run these applets. The instructions below, thanks to Reddit, should help you disable Java on every browser:
Disabling Java Plugin on Mozilla Firefox Browser:
Disabling Java Plugin on Google Chrome Browser:
Disabling Java Plugin on Opera Browser:
Disabling Java Plugin on Internet Explorer Browser:
Disabling Java Plugin on Safari Browser:
Note: Instead of uninstalling or deactivating Java, you can always update it. But as of now, there’s no Java update available, so it’s best to deactivate it.
To check if Java plugin has been successfully turned off, head over to this Java page (wait for the page to fully load) and you will be notified whether Java is still running actively in your browser. In that case, you may want to follow the above instructions once again, restart the browser, and revisit the Java page again.