Mozilla released Firefox 16 a couple of days ago, but abruptly removed the download from the company’s website on October 10, after a serious security vulnerability was discovered the day after its release. Mozilla’s director of security assurance announced the removal of the download on the Mozilla Security Blog and explained the details of the vulnerability.
He assured users that Firefox 15 wasn’t affected by the vulnerability and stated that the bug could allow a malicious website to potentially determine which websites users have visited and have access to the URL or URL parameters.
Users who had updated to version 16 are advised to downgrade to version 15.0.1 by following these instructions, until Mozilla has a fix ready for their browser. You can also opt to wait until Mozilla releases a patch fixing the issue.
Firefox 16 which was released on October 9 offered several new features including default VoiceOver support on Mac OS X, as well as initial Web app support for Windows, Mac and Linux
Mozilla released Firefox 15 in August which included code fixes for memory leaks and support for the Opus video format. Firefox 14 came in July with support for secure HTTPS connection when conducting Google searches.