iOS 12.1.2 (build 16C101) is an official Apple over-the-air update for the iPhone XS Max, released on 2018-12-17T21:06:21Z. The update package is 363.95 MB. This is a delta (partial) update that requires 12.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 85ce8f6138bc8bce2e1e1e1a9335db444b17bbc3.zip.