The WatchOS 5.3.1 includes “important security updates.” Apple has not published CVE entries for this update.
For MacBook users, macOS Mojave 10.14.6 supplemental update has been rolled out. The update, according to the release notes, resolves an issue that may cause certain Mac notebooks to shut down during sleep, fixes an issue that may degrade performance when working with very large files, and addresses an issue that may prevent Pages, Keynote, Numbers, iMovie, and GarageBand from updating.
As for the tvOS, the tvOS 12.4.1 which is available for Apple TV 4K and Apple TV HD, too fixes the same vulnerability as the one fixed for iPhones with iOS 12.4.1.
Apple is expected to roll out iOS 13, tvOS 13, as well as iPadOS 13 in the coming weeks after the company launches its 2019 iPhones. As it has been the case for years, the new OS is supposed to arrive after the new iPhones have been launched. Even though Apple has not announced the launch date, but as per leaks it is September 10. The new iPhones will run iOS 13 final version out-of-the-box. The upcoming software updates are available in beta versions and Apple users who want to join the beta testing program have to sign up on Apple’s beta testing website. This gives users access to iOS, macOS, and tvOS beta operating systems.