iOS 12.3 (build 16F5117h) is an official Apple over-the-air update for the iPhone X (GSM), released on 2019-03-27T17:06:21Z. The update package is 353.01 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: 94c5682761a406854b5e6389acc26504f2387efb.zip.