iOS 12.4 (build 16G5038d) is an official Apple over-the-air update for the iPhone XS Max, released on 2019-05-28T17:07:41Z. The update package is 298.02 MB. This is a delta (partial) update that requires 12.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 060716c59b3e7663006c22e878543856e70d3e7a.zip.