Apple have released iOS 12.4.2 to all iOS devices that are not supported by iOS 13.
At the moment, it’s unclear why Apple have released this update or what this update does, although it’s pretty much a guarantee that this update is a security update for devices that don’t run iOS 13.
iOS 12.4.2 is now available the following devices:
- iPhone 5S
- iPhone 6 and 6 Plus
- iPod touch 6th Generation
- iPad Air
- iPad mini 2
- iPad mini 3