Apple has issued January 2019 security patches for the following:
- iOS 12.1.3 for iPhones and iPads;
- macOS Mojave 10.14.3 for MacBooks, MacBook Pros, iMacs, iMac Pros, Mac Pros, etc.;
- tvOS 12.1.2 for Apple TV;
- Safari 12.0.3 for macOS Sierra 10.12.6, macOS High Sierra 10.13.5, and macOS Mojave 10.14.3 (it is bundled with Mojave 10.14.3);
- watchOS 5.1.3 for Apple Watch;
- iCloud for Windows 7.10 for Windows.
These are security updates, not feature updates, so please update as soon as possible.