iOS 13.3.1 (build 17D5026c) is an official Apple over-the-air update for the iPhone XS, released on 2019-12-17T18:13:27Z. The update package is 253.19 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: f7ee1dbf38a037b9a255737e0caacef2d1755ed2.zip.