iOS 8.4.1 (build 12H321) is an official Apple over-the-air update for the iPhone 5 (GSM), released on 2015-08-13T18:05:13Z. The update package is 420.17 MB. This is a delta (partial) update that requires 8.0.1 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: 3c27eaaa735a37e6b6a65147411fb9872f7ae542.zip.