iOS 13.3.1 (build 17D5026c) is an official Apple over-the-air update for the iPhone 8 Plus (GSM), released on 2019-12-17T18:13:26Z. The update package is 285.27 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: 7f3a57e38c8c847285b71ed662f84b09ffe345d0.zip.