As mentioned in this article, Apple has posted a new article on its website that details how a user can implement Full Mitigation for a “theoretical” speculative attack that targets Intel CPUs (central processing units). Full Mitigation is mostly for users that are at heightened risk for an attack, such as government workers or high-ranking business executives.
Enabling this mitigation results in an approximate 40% drop in performance. However, as previously mentioned, most users won’t need to enable this level of mitigation, as the attack is theoretical at this point and there are no known attacks in the wild for this.
macOS 10.14.5 includes the most relevant patches for users, although there have been reported issues from Mac users with some methods of file sharing over macOS. As always, it is the best practice to only download trusted software from the Apple App Store.
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