iPadOS 8.4.1 (build 12H321) is an official Apple over-the-air update for the iPad 3 (CDMA), released on 2015-08-13T18:05:08Z. The update package is 151.21 MB. This is a delta (partial) update that requires 8.3 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: d3db4eebb2e0b140bf14861bfa67fe50a2fa1733.zip.