www.lesswrong.com/posts/5CfBDiQNg9upfipWk/only-law-can-prevent-extinction

Anthropic's own April 7, 2026 announcement is narrower than this sentence.

On Anthropic's Project Glasswing page, the company says Mythos Preview found "thousands of high-severity vulnerabilities, including some in every major operating system and web browser." The same page later says Anthropic used Mythos Preview to identify thousands of zero-day vulnerabilities, "many of them critical, in every major operating system and every major web browser."

Anthropic's Frontier Red Team writeup uses the same narrower wording: Mythos Preview was capable of identifying and exploiting zero-day vulnerabilities in "every major operating system and every major web browser."

So the post overstates Anthropic's documented claim in two ways:

1. It drops the qualifier "major", turning a claim about major OSes/browsers into a claim about all operating systems and browsers.
2. It phrases the finding as "critical security vulnerabilities" across that whole set, while Anthropic's public wording is that Mythos found many critical vulnerabilities and some vulnerabilities in every major OS/browser.

That difference matters because the public evidence currently supports a claim about major platforms, not literally every operating system and browser.