I dismissed the earlier non-technical blog post as shameless product boosterism for Anthropic. The linked hacks blog (which is a better source than this article) is a welcome release. It's hard to deny there's something real to this now, I think. Mozilla's internal definition of a "vulnerability" is also probably more widely applied than what many would intuit, but it is good that these issues are being taken seriously and fixed.
At the same time other companies like AISLE are matching Mythos on vulnerabilities using older models but their own harnass: https://aisle.com/blog/aisle-matches-anthropic-mythos-on-fre...
So while Mythos certainly is real I think you could do the same with Deepseek pro, GPT 5.5 etc...
> The linked hacks blog
https://hacks.mozilla.org/2026/05/behind-the-scenes-hardenin...