iOS 12.3 (build 16F5156a) is an official Apple over-the-air update for the iPhone X (GSM), released on 2019-05-10T17:09:30Z. The update package is 451.5 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: d92e0b2a7f69c0a9f868601e2757ab82216016d7.zip.