Apple has issued an urgent OS X security patch to stop attackers from being able to remotely gain access to devices running either the El Capitan or Yosemite versions of the software, with the flaw understood to be related to recently discovered iOS vulnerabilities.
The patch addresses memory corruption and validation issues, which if exploited would give hackers kernel access on your machine – and from there, they could do pretty much whatever they wanted.
The update follows a patch for iOS devices running version 9.3.5 this week, which suffered from essentially the same issues. Last month, Citizen Lab said that human rights activist Ahmed Mansoor was the target of an attempted hack which – had he not been smart enough to avoid it – would have given attackers full access to the root of his iPhone.
In that instance, the SMS Mansoor received promised "new secrets" about detainees tortured in the United Arab Emirates if he clicked the included link. He didn't.
While you might not be a human rights activist or consider yourself a digital target, if you own an iPhone or any Mac computer, it's probably best to go ahead and update now, or risk being duped and spyware taking over your computer.
Related: Macbook (12-inch, 2016) review
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Will you be updating today or do you think the risk is quite low? Let us know in the comments below!