US Commerce orders export controls on Claude Fable 5 and Mythos 5; Anthropic disables both globally

What happened

On June 12, 2026 at 5:21 PM ET, Anthropic received an Is Informed letter from the Bureau of Industry and Security (BIS) invoking the Export Control Reform Act of 2018. Signed by Commerce Secretary Howard W. Lutnick, the letter mandates Anthropic obtain an individually validated export license to share Claude Mythos 5 and Claude Fable 5 with any foreign national anywhere — including its own foreign-national employees.

Context and impact

Fable 5 and Mythos 5 had launched only on June 9. Anthropic disabled both globally upon receipt, because it could not guarantee nationality-based restrictions would technically hold. The trigger, per reports, was a jailbreak vulnerability in Fable 5 that could bypass safety filters and expose advanced cybersecurity capabilities embedded in the Mythos 5 framework.

Details

• Legal basis: Export Control Reform Act 2018 (ECRA)
• Scope: all foreign nationals — inside and outside the US
• Impact: both models globally offline for everyone
• Older models: remain available, unaffected
• Trigger: alleged jailbreak vulnerability in Fable 5