On Tuesday, November 3, Mozilla released Firefox 42, addressing 18
security issues, three of which are rated critical. The newest version
of the browser also includes a feature called Private Browsing with
Tracking Protection that prevents websites from tracking users with
analytics software. The feature could cause some websites to appear
broken.
http://www.theregister.co.uk/2015/11/04/mozilla_patches_up_firefox_flaws/
