US government orders Anthropic to suspend all access to Fable 5 and Mythos 5, citing national security

US Government directive to suspend access to Fable 5 and Mythos 5

Anthropic stated the US government issued an export control directive on June 12 at 5:21 pm ET, ordering suspension of all access to Fable 5 and Mythos 5 by any foreign national, including foreign Anthropic employees. To comply, the company shut down both models for all users; other models are unaffected. The government cited a jailbreak method that bypasses Fable 5's safeguards, but Anthropic reviewed the demo and says it only exploited a few known minor vulnerabilities via a narrow, non-universal jailbreak—capabilities also available in other public models like GPT-5.5. Anthropic argues its safeguards are the strongest yet deployed, perfect jailbreak resistance doesn't exist in the industry, and its defense-in-depth strategy plus monitoring is the right approach. The company is complying but disagrees that a narrow jailbreak justifies recalling a model already deployed to hundreds of millions of users.

Why it matters: The US government has for the first time used export control authority to directly shut down two released frontier models, and Anthropic publicly pushed back, stating the jailbreak demo only found known minor vulns. This touches national security, model safety, and corporate c...