Just a quick reference of all the patches that fix the Meltdown bug (CVE-2017-5754) on Apple’s operating systems.

watchOS

Not impacted.

tvOS

Patched.
Version: 11.2
Release Date: 4th December 2017
Release Notes

iOS

Patched.
Version: 11.2
Release Date: 2nd December 2017
Release Notes

macOS

Patched.
Version: High Sierra 10.13.2
Patches for older versions:

• Security Update 2017-005 El Capitan
• Security Update 2017-002 Sierra

Release Date: 6th December 2017
Release Notes

More information on Meltdown/Spectre.
Apple’s Statement on Markdown/Spectre