A US export-control directive ordered Anthropic to block “foreign national” access to its top models Fable 5 and Mythos 5. Anthropic says that compliance forces it to disable both models globally—turning off a rollout that began June 9—even as the company argu
By the time the sun was still up on June 12, Anthropic’s most capable models had already slipped out of reach—this time not because of a technical failure, but because of a legal order.
The company says it received a US government export-control directive at 5:21pm ET that ordered it to block access to its two frontier AI models. Fable 5 and Mythos 5. by “foreign nationals.” The directive applies both inside and outside the United States. including Anthropic’s own foreign-national employees.
Anthropic’s response was immediate and sweeping: to comply, it had to disable both models for all customers worldwide. The fallout is blunt. Fable 5, which had been rolling out for free to millions, is now “currently unavailable” for everyone.
Fable 5 began its public rollout on June 9, offered to Pro, Max, and Enterprise customers through June 22. Three days later, the model that was meant to be broadly accessible is offline—starting with new sessions and also affecting existing ones.
In a developer notice, Anthropic said new sessions would fall back to a user’s default model or to Opus 4.8. Existing Fable 5 sessions would end with an error, and Platform requests to Fable 5 would fail as well. It told integrators to migrate to other models. All other Anthropic models, including Claude Opus 4.8, are unaffected.
Fable 5 and Mythos 5 are described as siblings. They share the same underlying model, but Fable adds safeguards. Anthropic says Fable blocks or diverts sensitive cybersecurity. biology. and chemistry queries. while the unrestricted Mythos 5 is limited to vetted government cyberdefenders and life sciences partners.
The directive doesn’t just change what the models can be used for; it changes who can even reach them. The company frames the order as a response to a reported way to jailbreak Fable 5. Anthropic says it reviewed a demo and found only minor. already-known bugs—issues it argues other publicly available models can discover without any bypass.
In its statement, Anthropic says the government has provided only verbal evidence of a potential narrow, non-universal jailbreak. The company describes that potential method as essentially asking the model to read a specific codebase and fix software flaws.
“ 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 said.
“Our understanding is that one potential jailbreak was shared with the government.”
Anthropic says it is complying with the order and removing access to both models for all users. At the same time, it argues against recalling a commercial model that had already been deployed to hundreds of millions of people.
“We are complying with the government’s legal directive and are removing access to Fable 5 and Mythos 5 for all users. However, we disagree that the finding of a narrow potential jailbreak should be cause for 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.”
The company says the capability it describes as being used for defense work is widely available elsewhere. It points to OpenAI’s GPT-5.5 and says that defenders use similar techniques every day.
Anthropic also insists the order is based on a misunderstanding and says it is working to restore access, promising more details within 24 hours.
Across the Atlantic, UK officials said the pause was felt on their side too. Kanishka Narayan MP. the UK’s Minister for AI and Online Safety. said the interruption affected customers in both the US and UK. describing it as a case for technological sovereignty. Narayan also referenced the UK government’s £1.1bn AI chip investment.
Taken together. the facts are hard to miss: a directive aimed at limiting access by foreign nationals resulted in a global shutdown of two flagship models. even though Anthropic argues the reported vulnerability is narrow and not universal. And a rollout that began June 9—free to Pro. Max. and Enterprise customers through June 22—was effectively stopped before it could reach the end of its promised window.
Anthropic Fable 5 Mythos 5 export control directive foreign national access AI safety Claude Opus 4.8 jailbreak technological sovereignty AI chips