After a diligent analysis of the test cases and our existing code, TenFourFox is not known to be vulnerable to the exploits repaired in Firefox 62.0.3/60ESR. Even if the flaws in question actually existed as such in our code, they would require a PowerPC-specific exploit due to some architecture-dependent aspects of the attacks.

http://tenfourfox.blogspot.com/2018/10/tenfourfox-and-hack2win.html