iOS 13.3.1 (build 17D5050a) is an official Apple over-the-air update for the iPhone XS, released on 2020-01-22T18:07:23Z. The update package is 252.47 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: 4a32602965ee21187d40ffda8a2292a546b1a1a0.zip.