tvOS 12.3 (build 16M5139a) is an official Apple over-the-air update for the Apple TV 4 (2015), released on 2019-04-22T17:08:28Z. The update package is 91.85 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: a4b98de63333cd3bcf47f515c3da08cd474d8bf5.zip.