I know this is just a reddit post, but it has links to lots of seemingly legit stuff saying this was put out by a company trying to manipulate AMD's stock price. Maybe try to get the stock to drop, buy big on the dip...and hope to make killer quick short while the stock recovers? Glad NVIDIA and Intel don't seem to be involved!
https://www.reddit.com/r/Amd/comments/845w8e/alleged_amd_zen_security_flaws_megathread/