It looks like the non-stop game of cat-and-mouse between developers as well as Apple has continued to rage on, where Cupertino has already stopped signing the iOS 8.1.2 firmware. In other words, the option to jailbreak the iPhone 6, iPhone 6 Plus, and all other iOS devices which have been chugging along to iOS 8.x is now closed.
Basically, the ‘signing’ of a version of iOS is a method that Apple takes advantage of in order to send out the message that a particular version of iOS happens to be up to date. In other words, just think of it as a kind of an expiration date, where the moment Apple stops signing a version, just like what it has done with iOS 8.1.2, then it ends up with an ‘expired’ tag to go along with it,
Jailbreakers would definitely take note of this, since iOS 8.1.2 makes use of an exploit which has now been patched in iOS 8.1.3 – where one would then have to perform a downgrade to iOS 8.1.2 n order to reap the full benefits of jailbreaking so that one can gain maximum system access. That is all in the past now, so those who would want to perform a jailbreak will have to play the patience card – at least until the next jailbreak solution arrives.