US asks Anthropic to restrict Fable, Mythos to US citizens
▼ Summary
– The US government issued an export control directive on June 12, ordering Anthropic to block foreign national access to its two most capable AI models, Fable 5 and Mythos 5.
– Anthropic suspended both models worldwide, as the order bars access by foreign nationals including its own employees, making compliance impossible without disabling the models for all users.
– The timing of the suspension is awkward, as Fable 5 had been released free to all Pro, Max, and Enterprise customers just three days prior, on June 9.
– Anthropic believes the order stems from a reported jailbreak of Fable 5, but the company argues it was a minor, non-universal bug that other public models can also discover.
– The UK Minister for AI and Online Safety criticized the pause, framing it as a case for technological sovereignty and pointing to the government’s £1.1bn AI chip investment.
Anthropic has been forced to temporarily suspend access to its most advanced AI models, Fable 5 and Mythos 5, for all users worldwide following a direct order from the US government. The directive, issued under national security authorities, bars access to both models by any foreign national, including Anthropic’s own employees who are not US citizens.
The order arrived at 5:21pm ET on June 12, and Anthropic says the only way to comply is to disable both models for every customer globally. Other Anthropic models, including Claude Opus 4.8, remain unaffected. The timing could hardly be worse. The company just began rolling out Fable 5 on June 9, offering it free to all Pro, Max, and Enterprise customers through June 22. A model handed to millions just three days ago is now offline for everyone.
Fable 5 is the safeguarded version of Mythos 5. Both share the same underlying model, but Fable includes additional safety layers that block or divert sensitive queries related to cybersecurity, biology, and chemistry. The unrestricted Mythos 5 is only available to vetted government cyberdefenders and life sciences partners.
In a developer notice, Anthropic explained that new sessions will fall back to a user’s default model or Opus 4.8, existing Fable 5 sessions will end with an error, and Platform requests to Fable 5 will fail. The company is urging integrators to migrate to other models.
UK Minister for AI and Online Safety Kanishka Narayan MP weighed in, noting that the pause affects customers in both the US and UK. He framed the incident as a case for technological sovereignty, pointing to the government’s £1.1bn AI chip investment.
Anthropic’s internal assessment suggests the order stems from a reported method to jailbreak Fable 5. The company says it reviewed a demo and found only minor, already-known bugs , the kind other publicly available models can discover without any bypass. “To date, the government has only given us verbal evidence of a potential narrow, non-universal jailbreak, which essentially consists of asking the model to read a specific codebase and fix any software flaws,” Anthropic stated. “Our understanding is that one potential jailbreak was shared with the government.”
The company is complying with the legal directive but disagrees that a narrow potential jailbreak warrants recalling a commercial model deployed to hundreds of millions of people. “If this standard was applied across the industry, we believe it would essentially halt all new model deployments for all frontier model providers,” Anthropic warned.
Anthropic points out that the same capability is widely available elsewhere, including in OpenAI’s GPT-5.5, and is used by defenders every day. The company maintains the order is a misunderstanding and says it is working to restore access, promising more details within 24 hours.
(Source: BleepingComputer)
