Why Anthropic suddenly pulled Fable 5 and Mythos 5 for everyone

Anthropic disabled two new Claude models (Fable 5 and Mythos 5) worldwide after a U.S. government export directive citing a reported narrow non‑universal jailbreak technique that allegedly allows the models to read and modify code; Anthropic disputes the severity and scope, notes similar capabilities exist in other models, and no public evidence of active exploitation or a widespread compromise has been presented.