Anthropic Shuts Fable 5 and Mythos 5 for All Users After AI Breached NSA Systems in Hours
Updated
Updated · Security Affairs · Jun 22
Anthropic Shuts Fable 5 and Mythos 5 for All Users After AI Breached NSA Systems in Hours
3 articles · Updated · Security Affairs · Jun 22
Summary
June 12 orders from the Trump administration forced Anthropic to cut off Fable 5 and Mythos 5 globally after requiring access be limited to U.S. citizens, a restriction the company could not verify in real time.
Senate testimony cited by The Economist said Mythos had broken into almost all classified NSA and U.S. Cyber Command systems within hours, according to Senator Mark Warner relaying comments from agency chief General Joshua Rudd.
Those claims remain unverified, but Anthropic had already kept Mythos off the public market and shared it with only about 200 Project Glasswing partners; the company says the model has found thousands of vulnerabilities, including a 27-year-old OpenBSD flaw.
The shutdown also cut off Five Eyes allies and the UK AI Security Institute while it was testing the systems, sharpening concerns that U.S. control over frontier AI access could leave foreign governments and researchers dependent on American providers.
Did the US just disarm its cyber defenders by locking away the world's most powerful security AI?
As America walls off its top AI, will every nation now race to build its own sovereign intelligence?
Global AI Blackout: The Sudden Suspension of Anthropic’s Fable 5 and Mythos 5 Under U.S. Government Order
Overview
On June 12, 2026, Anthropic abruptly disabled access to its advanced AI models, Fable 5 and Mythos 5, for all users worldwide after the U.S. government, under the Trump administration, issued an export control order. This action was triggered by Amazon flagging a jailbreak vulnerability and concerns that a group possibly linked to China had accessed Mythos. Anthropic explained it could not reliably separate users by nationality in real-time, leading to a global shutdown. The event highlighted the risks of powerful AI, the challenges of government intervention, and sparked debates about transparency, security, and the future of AI governance.