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 251.83 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: ec45fe165dfc5ebad448d9d248d6e2d35be39de1.zip.