iOS 12.3 (build 16F5155a) is an official Apple over-the-air update for the iPhone X (GSM), released on 2019-05-07T17:04:15Z. The update package is 451.52 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: e53491cbd673c693b6ceb2a1968ccdad8c24aa6f.zip.