A group of users leaked Anthropic's AI model Mythos by reportedly guessing where it was located - Fortune

Anthropic's latest wonder — Claude Mythos Preview — has been gatecrashed by a bunch of users who reportedly just *guessed the URL* and got in. Security researchers claim a 'small group' successfully accessed the model without authorisation, because apparently the safety-conscious lab's crown jewels were hiding behind what amounts to a sticky note saying 'try /mythos-preview-beta-v2'. CEO Dario Amodei is said to be 'investigating,' which in tech translation means they're now panic-scanning access logs while denying anything truly valuable was exposed. That $61.5 billion valuation the company just flaunted might want to buy a better lock.

The breach isn't exactly the Pentagon Papers — the exposed instance was a Preview model, not the final production version — which is about as comforting as being told your burglar only stole the *prototype* combination lock. Anthropic has been leaning heavily on its safety narrative as a competitive moat against OpenAI's faster-but-wilder release cadence. Having unauthorised users walk through the front door while that alleged safety vault was supposedly under CCTV makes the whole sales pitch look a bit daft, really.

FORTUNE helpfully notes that the model is called Mythos — precisely the kind of legendarily tragic name that practically writes its own cautionary tale. OpenAI got breached earlier this year when someone discovered an unlisted API key in a public GitHub repo. We called these security shenanigans an 'industrial-scale' joke when China did it; now we find everyone's fingerprints at the cookie jar, and the jars sell for sixty billion dollars unlocked.