iOS 11.3 (build 15E5216a) is an official Apple over-the-air update for the iPhone 8 (GSM), released on 2018-03-16T17:05:16Z. The update package is 66.55 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: 561ab252e7b59b7804fa5b7d6fdcd2691e022716.zip.