iOS 13.3.1 (build 17D5026c) is an official Apple over-the-air update for the iPhone 11, released on 2019-12-17T18:13:29Z. The update package is 253.66 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: a1be6dbde8f113a336b1eba1a48d31399b9d3378.zip.