Anthropic Disables Fable 5 and Mythos 5 Following Government Order

Anthropic shut down access to its Fable 5 and Mythos 5 AI models on Friday after receiving a U.S. government export control directive citing "national security authorities." The company received the order at 5:21 p.m. ET.

The directive instructed Anthropic to suspend all access to the models "by any foreign national, whether inside or outside the United States, including foreign national Anthropic employees." Anthropic disabled the models for all customers to ensure compliance. All other Anthropic models remain accessible.

Recent Model Releases

The shutdown comes days after Anthropic announced both models as state-of-the-art releases. According to the company, Fable 5 marked the first time Anthropic released such an advanced model to the public, enabled by new safeguards that block responses in specific high-risk areas.

The models built on Claude Mythos Preview, which Anthropic released in April 2026 with advanced cybersecurity capabilities. The company limited Mythos Preview to a select group of companies as part of Project Glasswing, a cybersecurity initiative, and did not plan general availability.

What This Means

This marks an unprecedented intervention by U.S. authorities in commercial AI model deployment. The order's scope—extending to foreign national employees within the U.S.—suggests concerns beyond standard export controls. The timing, just days after release, indicates either newly discovered capabilities that triggered national security review or a policy shift in how advanced AI systems are regulated. Other AI companies releasing frontier models may face similar restrictions.