The Tor Project released the Tor Browser 6.0, the last version of the popular Tor browser that brings along significant privacy and security improvements. The Tor Browser uses HTTPS-Everywhere 5.1.9 to preserve the privacy of its users on all platforms, including OS X. One of the most significant enhancement is the ending of support for SHA1 certificates. The SHA-1 hash algorithm is vulnerable to collision attacks that will be soon possible, in 2012 experts demonstrated how breaking SHA1 is becoming feasible.”]
Source: https://securityaffairs.co/wordpress/47949/digital-id/tor-browser-6-0.html