Anthropic disables Fable 5 and Mythos 5 after US order targeting foreign-national access
Anthropic says a US export-control directive required it to block foreign nationals from accessing Fable 5 and Mythos 5, leading the company to suspend the models for all customers to ensure compliance.
Anthropic has disabled access to Claude Fable 5 and Claude Mythos 5 after receiving a US government export-control directive on 12 June 2026.
The directive did not order a general public shutdown of the models. According to Anthropic, it required the company to suspend access for any foreign national, whether inside or outside the United States. The company said this also included foreign national Anthropic employees.
Anthropic said the practical effect was broader. Because it needed to ensure compliance with the nationality-based restriction, it removed access to Fable 5 and Mythos 5 for all customers. Access to other Anthropic models was not affected.
The company said the government cited national security authorities but did not provide specific details of its concern. Anthropic said it understands the directive to relate to a possible method for bypassing, or jailbreaking, Fable 5.
A jailbreak is a technique used to push an AI model around its safety safeguards. In cybersecurity contexts, this can raise concerns if a model can be made to provide information that helps identify or exploit software vulnerabilities.
Anthropic said it reviewed a demonstration of the technique and found that it appeared to identify a small number of previously known, minor vulnerabilities. The company argued that other publicly available models could identify similar issues without using the same bypass.
Anthropic defended Fable 5’s safeguards, saying the model had been tested before launch by internal teams, the US government, the UK AI Safety Institute, and private third-party organisations. It said no tester had found a universal jailbreak capable of broadly bypassing the model’s protections.
The company said perfect resistance to jailbreaks is unlikely to be possible for any current AI model. It said Fable 5 was therefore built around a defence-in-depth strategy, combining stronger safeguards, monitoring, and 30-day customer data retention to help detect and respond to misuse.
Anthropic said it is complying with the directive but disagrees that a narrow potential jailbreak should justify removing access to a deployed commercial model. It said it is working to restore access as soon as possible.
