http://wccftech.com/saigon-jailbreak-for-ios-10-2-1-released-for-64-bit-iphone-and-ipads/

Apple released its iOS 11 firmware to all users not so long ago. While at this point we are anxiously waiting for an iOS 11 jailbreak, a hacker named Abraham Masri released an iOS 10.2.1 jailbreak for all 64-bit iPhone and iPads. Previously, the Cupertino giant released the iOS 10.2.1 to users in an attempt to kill the Yalu jailbreak in January. The update patched all the vulnerabilities that were necessary for the Yalu jailbreak for iOS 1- – iOS 10.2. So let;s dive in to see some more details on the new Saïgon jailbreak by the hacker.

As we have mentioned earlier, Abraham Masri released the Saïgon jailbreak for iOS 10.2.1 for 46-bit iOS devices. However, at this point, if your iOS device is running any firmware higher than iOS 10.2.1 than it might be impossible to downgrade to it. This is because the company stopped signing iOS 10.2.1 in February, locking the doors to any possible downgrade option. Henceforth, if your iOS device is currently running the iOS 10.2.1. only then will you be able to take advantage of the new Saïgon jailbreak.