iOS 12.3 (build 16F5156a) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2019-05-10T17:09:38Z. The update package is 45.19 MB. This is a delta (partial) update that requires 12.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 79f282eec74ba0d4f53f7484a31f9fb386800f07.zip.