Mozilla + Anthropic Mythos Found 271 Firefox Bugs — Mozilla Says 'Zero-Days Are Numbered'

Mozilla Blog / Hacker News (40pts)·high signal

Mozilla published a blog post titled 'The zero-days are numbered' detailing how Claude Mythos Preview found and fixed 271 security vulnerabilities in Firefox 150, up from 22 bugs in Firefox 148 with Opus 4.6. Mozilla states there is no category of vulnerability that humans can find that the model can't. The key insight: gap between machine-discoverable and human-discoverable bugs erodes the attacker's advantage by making all discoveries cheap. Wired's coverage (36pts HN) and Ars Technica both confirmed the findings independently.