iOS 13.3.1 (build 17D5050a) is an official Apple over-the-air update for the iPhone 8 (GSM), released on 2020-01-22T18:07:22Z. The update package is 194.99 MB. This is a delta (partial) update that requires 13.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: bed302b76924ccb74895f0896248faa299d99433.zip.