Ok the vulnerability was initially found by Tavis Ormandy at Project Zero https://bugs.chromium.org/p/project-...detail?id=1524

Now that issue remains open and has not yet been closed that is why some trackers are still NOT allowing all uTorrent 3.*.* versions , since Tavis does not seem to have retested the latest patch from uTorrent. He did test their first attempt and it failed badly, but they have released another version after that. By the way the way they tried to patch it the first time indicates uTorrent devs have no idea what there doing.

That said Tavis has recently tweeted "Yes, I believe there's been a new update that solves all the problems reported." https://twitter.com/taviso/status/971494080852250627

Notice that he says "believe" further indicating it is not been tested.

As for v2 it appears that the code needed to exploit the vulnerability had not been built until after v2 . V2 should be allowed and is on many trackers until a vulnerability is found in it.

To sum it all up everyone seems to be waiting on Tavis at project Zero to give the uTorrent patch the ok.