Apart from the click-bait headline, I think the actual content is valid.
Yes, and if the fake news had been in the first three sentences, you could have said "apart from the first three sentences, the actual content is valid". The headline was still posted by CNN, supposedly as part of a news article. They're not blameless just because the fakery is in the headline, especially since the headline is the part that the most people will see. A month later people won't remember exactly where they read that math is racist, but they'll have the idea in their head.
(Of course, "math is racist" is so absurd that people might reject it anyway, but they might remember a more plausible sounding but still fake one.)