Tech firms are working to fix bugs that could allow hackers to steal personal data from computer systems.
Google researchers said there were “serious security flaws” in chips made by Intel, AMD and ARM, affecting 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.