Apple Addresses Meltdown and Spectre in macOS Sierra and OS X El Capitan With New Security Update

Along with macOS High Sierra 10.13.3, Apple this morning released two new security updates that are designed to address the Meltdown and Spectre vulnerabilities on machines that continue to run macOS Sierra and OS X El Capitan.

As outlined in Apple's security support document, Security Update 2018-001 available for macOS Sierra 10.12.6 and OS X El Capitan 10.11.6 offers several mitigations for both Meltdown and Spectre, along with fixes for other security issues, and the updates should be installed immediately.

meltdownspectre
Apple addressed the Meltdown and Spectre vulnerabilities in macOS High Sierra with the release of macOS High Sierra 10.13.2, but older machines were left unprotected. Apple initially said a prior security update included fixes for the two older operating systems, but that information was later retracted.

Spectre and Meltdown are two hardware-based vulnerabilities that impact nearly all modern processors. Apple in early January confirmed that all of its Mac and iOS devices were impacted, but Meltdown mitigations were introduced ahead of when the vulnerabilities came to light in iOS 11.2 and macOS 10.13.2, and Spectre was addressed through Safari updates in iOS 11.2.2 and a macOS 10.13.2 Supplemental Update.

Spectre and Meltdown take advantage of the speculative execution mechanism of a CPU. As these use hardware-based flaws, operating system manufacturers are required to implement software workarounds. These software workarounds can impact processor performance, but according to Apple, the Meltdown fix has no measurable performance reduction across several benchmarks.

The Spectre Safari mitigations have "no measurable impact" on Speedometer and ARES-6 tests, and an impact of less than 2.5% on the JetStream benchmark.

Many PCs with Intel processors have been facing serious issues following the installation of patches with fixes for Meltdown and Spectre, but these problems do not appear to impact Apple's machines.

Related Forum: macOS High Sierra

Popular Stories

iphone 17 models

No iPhone 18 Launch This Year, Reports Suggest

Thursday January 1, 2026 8:43 am PST by
Apple is not expected to release a standard iPhone 18 model this year, according to a growing number of reports that suggest the company is planning a significant change to its long-standing annual iPhone launch cycle. Despite the immense success of the iPhone 17 in 2025, the iPhone 18 is not expected to arrive until the spring of 2027, leaving the iPhone 17 in the lineup as the latest...
duolingo ad live activity

Duolingo Used iPhone's Dynamic Island to Display Ads, Violating Apple Design Guidelines

Friday January 2, 2026 1:36 pm PST by
Language learning app Duolingo has apparently been using the iPhone's Live Activity feature to display ads on the Lock Screen and the Dynamic Island, which violates Apple's design guidelines. According to multiple reports on Reddit, the Duolingo app has been displaying an ad for a "Super offer," which is Duolingo's paid subscription option. Apple's guidelines for Live Activity state that...
Clicks Communicator Feature

'Clicks Communicator' Unveiled — Will You Carry This With Your iPhone?

Friday January 2, 2026 6:35 am PST by
The company behind the BlackBerry-like Clicks Keyboard accessory for the iPhone today unveiled a new Android 16 smartphone called the Clicks Communicator. The purpose-built device is designed to be used as a second phone alongside your iPhone, with the intended focus being communication over content consumption. It runs a custom Android launcher that offers a curated selection of messaging...
Low Cost A18 Pro MacBook Feature Pink

Apple's 2026 Low-Cost A18 Pro MacBook: What We Know So Far

Friday January 2, 2026 4:33 pm PST by
Apple is planning to release a low-cost MacBook in 2026, which will apparently compete with more affordable Chromebooks and Windows PCs. Apple's most affordable Mac right now is the $999 MacBook Air, and the upcoming low-cost MacBook is expected to be cheaper. Here's what we know about the low-cost MacBook so far. Size Rumors suggest the low-cost MacBook will have a display that's around 13 ...
Low Cost MacBook Feature A18 Pro

Low-Price 12.9-Inch MacBook With A18 Pro Chip Reportedly Launching Early This Year

Friday January 2, 2026 9:08 am PST by
Apple plans to introduce a 12.9-inch MacBook in spring 2026, according to TrendForce. In a press release this week, the Taiwanese research firm said this MacBook will be aimed at the entry-level to mid-range market, with "competitive pricing." TrendForce did not share any further details about this MacBook, but the information that it shared lines up with several rumors about a more...
Apple Fitness Plus hero

Apple Announces New Fitness+ Workout Programs, Strava Challenge, and More

Friday January 2, 2026 6:43 am PST by
Apple today announced a number of updates to Apple Fitness+ and activity with the Apple Watch. The key announcements include: New Year limited-edition award: Users can win the award by closing all three Activity Rings for seven days in a row in January. "Quit Quitting" Strava challenge: Available in Strava throughout January, users who log 12 workouts anytime in the month will win an ...
govee floor lamp

CES 2026: Govee Announces New Matter-Connected Ceiling and Floor Lights

Sunday January 4, 2026 5:00 am PST by
Govee today introduced three new HomeKit-compatible lighting products, including the Govee Floor Lamp 3, the Govee Ceiling Light Ultra, and the Govee Sky Ceiling Light. The Govee Floor Lamp 3 is the successor to the Floor Lamp 2, and it offers Matter integration with the option to connect to HomeKit. The Floor Lamp 3 offers an upgraded LuminBlend+ lighting system that can reproduce 281...
Belkin 25W Battery magnetic

CES 2026: Belkin Announces Magnetic Ring Power Bank, Modular Dock, and More

Sunday January 4, 2026 3:02 pm PST by
Belkin today announced a range of new charging and connectivity accessories at CES 2026, expanding its portfolio of products aimed at Apple device users. UltraCharge Pro Power Bank 10K with Magnetic Ring The lineup includes new Qi2 and Qi2.2 wireless chargers, magnetic power banks, a high-capacity laptop battery, and USB-C productivity accessories, with an emphasis on higher charging...

Top Rated Comments

nexu Avatar
104 months ago
Can we get the same for iOS 10?
Score: 12 Votes (Like | Disagree)
Paddle1 Avatar
104 months ago
How about iOS 9 or iOS 10? Lots of devices stuck there.
Score: 12 Votes (Like | Disagree)
zorinlynx Avatar
104 months ago
I wonder how reliable Apple's patches are given that Linus Torvalds has condemned the patches ('https://lkml.org/lkml/2018/1/21/192') submitted to the linux kernel by Intel:




Linus is never one to mince words...
That's one thing I love about him. He loves Linux and he wants to make it the best system it can be. He doesn't bother with political correctness or being nice. If someone writes bad code, he lets them know, harshly. Everyone who works with him knows not to take things personally.

We need more people like that in QC and management positions at companies like Apple. Steve Jobs was much the same way.
Score: 11 Votes (Like | Disagree)
vicviper789 Avatar
104 months ago
i guess my ibook g4 will be left vulnerable...
Score: 6 Votes (Like | Disagree)
lionel77 Avatar
104 months ago
So, no fixes for Yosemite...
Is it possible to just get El Capitan or Sierra instead of the useless High Sierra...?
Yes, fortunately you can still get those installers:
https://support.apple.com/en-us/HT208202 (Sierra)
https://support.apple.com/en-us/HT206886 (El Capitan)
Score: 6 Votes (Like | Disagree)
Dangermen Avatar
104 months ago
I shouldn't really reply to someone that joined in October 2017 only to post criticism (not a single positive post).
However, I will point out that one could say all security measures are "half-hearted" in that they address an issue (or a group of them) when many others are either in the pipeline or about to be discovered.
If you cannot get to terms with this fact of computing life then perhaps you should give up computers altogether.

I hate to point out the obvious, but when I am not happy with a service provider I usually move to one that I perceive to be a better one. Have you considered this as an option?
Since when does being a forum member for a short period of time exclude my opinion? I've been in IT for 28 years. I started with Linux and I've been a Mac user for 7 years now. I'm heavily invested in them. Switching isn't A) cheap nor B) is my opinion not the source of the problem.

I am asking for Apple to just be more transparent. As an example, pick the last year of the OS release your running that isn't the current OS, then add up all of the discovered vulnerabilities in the following years and those are the holes you are running with. e.g. a 2015 OS has 540+ holes Apple will -never- fix. So patching spectre and meltdown isn't throwing anyone a bone.
https://www.cvedetails.com/product/15556/Apple-Iphone-Os.html?vendor_id=49

Cisco is not a perfect company but their EOL policy is transparent and certainly works better than Apples. They could learn something from them.
https://www.cisco.com/c/en/us/products/eos-eol-policy.html

Asking Apple to do better is not picking on them, I'm a very concerned customer. I had to dump a fully functional Mac mini because Apple stopped producing patches. That latest iMessage crash bug, not fixed in Sierra. I now have a new mac.

---

One last thing, I joined in October because of precisely this issue. I want to raise awareness so that Apple improves their response, not continue with it's current fog of a policy.
Score: 5 Votes (Like | Disagree)