Till then download, install and use the official Firefox version from Ubuntu:
http://packages.ubuntu.com/trusty-updates/firefox
If Mint version doesn't get fix or upgrade soon I will add this or similar information in fixes post.
Edit: Or to make it easier use apt-get to install the Ubuntu version:
Code: Select all
sudo apt-get update
sudo apt-get install firefox=44.0.2+build1-0ubuntu0.14.04.1