iOS 11.3 (build 15E5178f) is an official Apple over-the-air update for the iPhone X (GSM), released on 2018-02-06T18:21:25Z. The update package is 332.02 MB. This is a delta (partial) update that requires 11.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 91941e6ab200104c3ef8c86e80c946a7b14a12b2.zip.