https://wccftech.com/watchos-5-3-1-tvos-12-4-1-and-macos-10-14-6-supplemental-update-released/

Apple has released watchOS 5.3.1, tvOS 12.4.1 and macOS 10.14.6 supplemental update with minor fixes and improvements.

In a surprising move, Apple released software updates without issuing a beta first, something that has turned into a rarity these days. These updates are available for Apple Watch, Apple TV and Mac users.