A massive security flaw thought to affect millions of computers has been discovered in the design of Intel's processors, which could give hackers your passwords.
Details of the exact extent and nature of the bug are being kept under wraps while programmers work to fix the issue.
But it is believed to be found in Intel chips manufactured over the past decade.
It is likely that most Windows and Mac OS users will have to download a patch that may slow down your system's performance by up to 50 per cent.
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A massive security flaw thought to affect millions of computers has been discovered in the design of Intel's processors, which could give hackers your passwords. Details of the exact extent and nature of the bug are being kept under wraps while programmers work to fix it
At the moment, there is nothing users can do to address the security flaw.
Programmers for the Linux open-source operating system are reportedly working to overhaul the affected memory areas.
Microsoft Corp is expected to issue a Windows patch next Tuesday after circulating test fixes towards the end of 2017.
Similar operating systems, such as Apple's 64-bit macOS, will also need to be updated.
'Crucially, these updates to both Linux and Windows will incur a performance hit on Intel products,' The Register wrote.
'More recent Intel chips have features to reduce the performance hit. Your mileage may vary.
'The effects are being benchmarked, however we are looking at a ballpark figure of a five to 30 per cent slowdown, depending on the task and the processor model.'
The vulnerability affects the Intel x86-64 series of chips, which includes most Windows and Linux desktop and servers equipped with the company's CPUs, as well as many Apple devices.
An unknown flaw in the way the processor accesses an area of the operating system called the kernel memory could let hackers read its contents The Register reported, citing unnamed sources.
This may include passwords and other login details, as well as the contents of files and other sensitive data.
Normally, the contents of the kernel memory is protected from being read by software being run on a computer.
The flaw would let an attacker write a piece of code to reveal its hidden treasure trove of data.
To fix the error, software engineers will need to redesign the way the kernel memory interacts with software processes running on a device.
However, this is likely to mean a major hit on a computer's performance, experts say.
Speaking to Sky News, computer scientist and president of virtual hardware firm Bromium, Ian Pratt, said: 'Some things will end up