Tech firms are working to fix bugs that could allow hackers to steal personal data from computer systems.
Google researchers said the "serious security flaws" affected chips made by Intel, AMD and ARM, and the devices which use them.
The industry has been aware of the problem for months and hoped to solve it before details were made public.
The UK's National Cyber Security Centre (NCSC) said there was no evidence that the vulnerability had been exploited.
Some fixes, in the form of things like software updates, have been introduced or will be available in the next few days, said Intel, which provides chips to about 80% of desktop computers and 90% of laptops worldwide.
Analysis by Chris Foxx, technology reporter
Often when researchers discover a security problem, they share the information with the affected company so the issue can be fixed.
Typically, both parties agree not to publicise the problem until a fix has been implemented, so that criminals cannot take advantage of the issue.
This time it looks like somebody jumped the gun and information was leaked before a software fix was ready for distribution.
Intel said it had planned to share information next week, and several security researchers have tweeted that they have made a secrecy pact with the chip-maker.
That leaves the company in an uncomfortable situation, with a widely-publicised problem before the fix is ready to go.
Microchips are the basic electronic systems behind many devices such as computers and mobile phones
The issue was originally linked to a flaw only in Intel's chips, but the firm said this was "incorrect".
"Many types of computing devices – with many different vendors' processors and operating systems – are susceptible to these exploits," said Intel.
ARM said patches had already been shared with its customers, which include many smartphone manufacturers.
AMD said it believed there was "near zero risk to AMD products at this time."
On a conference call for investors, Intel said researchers had shown that hackers could exploit vulnerabilities, gaining the ability to read memory and potentially access information such as passwords or encryption keys on devices.
Microsoft and Apple – which both use Intel chips – are expected to roll out security updates soon.
The NCSC said it was aware of the reports of the potential flaw and advised that all organisations and home users "continue to protect their systems from threats by installing patches as soon as they become available."
Experts advised caution on the issue.
"It is significant but whether it will be exploited widely is another matter," said Prof Alan Woodward, from the University of Surrey.