iOS 12.3 (build 16F5129d) is an official Apple over-the-air update for the iPhone XS Max, released on 2019-04-08T17:05:04Z. The update package is 399.94 MB. This is a delta (partial) update that requires 12.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 107a10abd9acf2c61161a650b8cb33dd7b8be4fd.zip.