Anthropic Disables Claude Fable 5 and Mythos 5 Globally After U.S. Order

• Anthropic shut down Claude Fable 5 and Mythos 5 globally after a June 12 U.S. order.
• Fable 5 sessions now error out, while users shift to Opus 4.8 or older models.
• The dispute moves AI export controls from chips toward direct access to deployed models.

Anthropic disabled access to Claude Fable 5 and Mythos 5 after a U.S. Commerce Department order blocked foreign access to the models. The shutdown followed a directive received at 5:21 p.m. ET on June 12.

The order cited national security authorities and applied to foreign nationals inside and outside the U.S., including foreign national employees. Because the company said it could not reliably separate affected users, the models were disabled globally.

The directive marked a wider turn in American AI controls, which had mostly targeted chips, tools, and infrastructure. This action instead restricted access to deployed AI systems, placing commercial model availability inside the national security debate.

However, AnthropicAI said access to all other Claude models was not affected. New sessions across Claude products were moved to a selected default model or Opus 4.8, while existing Fable 5 sessions ended with errors.

On the Claude Platform, requests to Fable 5 also began returning errors. Developers were told to update integrations to other models, creating immediate disruption for teams using the system in production.

The company said the government did not provide specific details about the national security concern. However, it believes officials became aware of a method for bypassing or jailbreaking Fable 5. After reviewing a demonstration of the technique, the company said it identified a small number of previously known, minor vulnerabilities.

Those issues appeared simple and could also be found by other publicly available models. The company argued that a narrow potential jailbreak should not justify recalling a commercial model deployed to hundreds of millions of people.

The shutdown drew complaints from developers who lost access to active workflows. Some described the move as self-inflicted, while others framed it as government overreach.

The order arrived after a separate dispute between Trump administration officials and the IPO-bound company had begun to ease. That rupture followed its refusal to support military use of models for domestic surveillance and fully autonomous weapons systems.

Pentagon chief information officer Kirsten Davies backed the national security stance on X, saying some priorities outweighed revenue cycles and pre-IPO valuation.

The company had called for stronger U.S. oversight of AI two days earlier. However, it said Friday’s action did not follow fair, fact-based regulation.

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