Claude Fable 5. The Day Anthropic Let the Dangerous Model Out, With a Leash.

Welcome to Learn AI from AI. I am Brian.

If you have been following this show, you remember a story we covered a few weeks ago that I called one of the strangest things in AI.

Anthropic built a model so powerful, and so dangerous, that they refused to release it. They called it Mythos. It could find security vulnerabilities in every major operating system and every major web browser on earth. And their decision was simple. The public does not get this. Too risky.

Well, on June ninth, 2026, that changed.

Anthropic released Claude Fable 5. And here is the headline that matters. Fable 5 is the first publicly available Mythos-class model. In other words, they finally let a version of the dangerous model out of the lab. But they did something clever to do it safely. And understanding that one clever trick is the most important AI lesson of the month.