US government orders Anthropic to suspend Fable 5, Mythos 5 access

The US government issued an emergency export control directive, forcing Anthropic to disable Fable 5 and Mythos 5 for all customers, citing a potential jailbreak vulnerability. Anthropic disputed the severity, stating the vulnerability is simple and replicable by other models like GPT-5.5. The company warned the precedent could halt future frontier model deployments.