Похоже, что Meltdown исправлен в macOS X 10.12 и 10.11
https://support.apple.com/en-gb/HT208331Kernel
Available for: macOS High Sierra 10.13.1, macOS Sierra 10.12.6, OS X El Capitan 10.11.6
Impact: An application may be able to read kernel memory
Description: Systems with microprocessors utilizing speculative execution and indirect branch prediction may allow unauthorized disclosure of information to an attacker with local user access via a side-channel analysis of the data cache.
CVE-2017-5754: Jann Horn of Google Project Zero, Werner Haas and Thomas Prescher of Cyberus Technology GmbH, and Daniel Gruss, Moritz Lipp, Stefan Mangard and Michael Schwarz from Graz University of Technology
Entry added January 4, 2018