WikiLeaks says the thousands of documents from what it calls "Vault 7" are only the first in a series it is planning to release on the CIA.
European-based cybersecurity writer Raphael Satter says it appears to be WikiLeaks' most daring release yet.
"These documents - I've been able to examine a subset of them - they appear to be very technical in nature, and they're related to the CIA hacking tools that are used to break into everyday devices. These could be smartphones, like iPhones or Android devices, or could even be smart televisions, like Samsung televisions, that are turned into actual impromptu microphones."
WikiLeaks says it has published a description of hacking methods but not enough information to allow hackers to use the techniques.
Washington Post intelligence reporter Greg Miller has told the ABC the way WikiLeaks has chosen to release the data is interesting.
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"They are putting out descriptions of the files and then withholding, or holding back, at least for now, the raw code, or at least that's what they're saying they're doing. So they're describing various exploits - basically, ways that the agency uses hacking tools and code to take over everyday devices that millions of people use."
The CIA says it does not comment on the authenticity or content of purported intelligence documents.
But BBC security analyst Gordan Corera says the leaks will be worrying for the CIA if they are authentic.
"Because it tips off its potential targets to what they can do, and people then change their behaviour, potentially, so that they can't be spied on. That's the argument from the intelligence agencies why this material shouldn't be out there. The argument from WikiLeaks, though, is that it's in the public interest to know that some of these consumer devices - devices that everyone uses - are insecure and vulnerable to hackers of any type, who can get into them and exploit those vulnerabilities, and that the CIA itself knew that and didn't tell the companies to secure them."
Edward Snowden, the former contractor for the National Security Agency who exposed active surveillance programs in 2013, says the leak appears authentic and is significant.
Posting on Twitter, he said the reports were evidence the US government had developed security vulnerabilities in US products and left them there.
He says it means hackers can exploit security cracks to break into any iPhone in the world.
Former British army major-general Jonathan Shaw has told Sky News the latest leak must be seen in the context of current competition for global credibility.
"It's very much in the interests of the Russians that the CIA should be discredited. You could also say that, in the context of the Washington politics at the moment, it's very much in President Trump's interests to see the CIA discredited. So I think we need the timing of this leak in that geopolitical context."
WikiLeaks has been facing questions over its ties with Russia.
Edward Snowden is currently in Russia, where he is a so-called "guest" of President Vladimir Putin and is protected until at least 2020.
Critics of WikiLeaks claim it is backed by Russia.
WikiLeaks founder Julian Assange has insisted neither the Russian government nor a state party provided the hacked emails that damaged Hilary Clinton's US campaign.
But a US intelligence report concluded Russian military sources had fed those emails to WikiLeaks.
