Anthropic Ships Claude Fable 5 with Exploit Generation
Anthropic's Mythos 5 and Claude Fable 5 represent the arrival of frontier AI models with demonstrated, advanced vulnerability discovery and exploit-development capabilities — a capability class that will rapidly proliferate across multiple vendors and open-weight releases. The core attack surface is not model-specific: guardrail bypass of the consumer-facing Fable 5 exposes full Mythos-grade offensive capability to any actor who can defeat the content filters, while the broader proliferation trajectory means defenders must assume adversary access to equivalent capabilities within months. The regulatory response addresses a single vendor while doing nothing to raise the floor for the broader ecosystem of competitive and open-weight models following close behind.