iOS 13.3.1 (build 17D5050a) is an official Apple over-the-air update for the iPhone 8 (GSM), released on 2020-01-22T18:07:21Z. The update package is 191.19 MB. This is a delta (partial) update that requires 13.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 8da76c30aa9e373db39051a5301a20cf43a84bb8.zip.