I'm thinking North Korea. But Israel was my first guess too. Basically, just information that's already public knowledge anyway.
But it sounds like they're conflating things. All of it defies common sense also. There would be a relatively large number of military and intelligence officials that would have a need to know justification on capabilities in order to wage war on our enemies and protect our sovereignty.
It's preposterous to think there's information so secret that only cabinet level positions would have this knowledge. And, that information would also be needed by so many to defend our nation. That's why I think they're conflating things. Like, here's a nugget that came from the CIA so it is uber secret even though the public already knows this. And considering this was a coordinated leak, it's also probable that this was a poison pill intentionally deposited on the document for just this purpose.
But I don't put any credit to the story anyway.