Anthropic has been forced to abruptly disable its latest AI model, Claude Fable 5, just days after its public release, after the US government ordered the company to block foreign nationals from using it. The dramatic step, taken late last night, also applied to non-American nationals who worked on the model, the company said in a statement.
“The net effect of this order is that we must abruptly disable Fable 5 and Mythos 5 for all our customers to ensure compliance,” Anthropic wrote. The company self-described the model as “too powerful” ahead of its launch, a claim some critics dismissed as marketing hype.
“Anthropic disabled its 'too powerful' Fable 5 AI model after US ordered it to block foreign nationals, citing jailbreaking risks.”
US national security authorities did not identify specific concerns, but Anthropic said: “Our understanding is that the government believes it has become aware of a method of bypassing, or ‘jailbreaking’ Fable 5.” Jailbreaking is a technique used to bypass software restrictions, potentially allowing hackers to access sensitive information. The company reviewed a demonstration of the technique and found it could identify “a small number of previously known, minor vulnerabilities.” Anthropic added that other publicly available models can discover the same vulnerabilities without needing a bypass.
Claude Fable 5 is a version of Anthropic’s Claude Mythos, competing with OpenAI’s ChatGPT and Google’s Gemini. The company had touted safeguards against cyber hacking and initially released Fable 5 privately in April for vulnerability testing, before making it public this week. Finance, technology and government leaders had expressed concerns about the public rollout, the company noted.
The order comes amid a separate ongoing lawsuit between Anthropic and the Trump administration over a directive to stop government agencies using the company’s AI tools. The BBC has approached the US Department of Commerce for comment.
The European Union, which gained access to Mythos earlier in June after weeks of talks, said the development “further underlines Europe’s need for technological sovereignty.” Thomas Regnier, a spokesman for the European Commission, said: “We take note of Anthropic’s statement and are assessing.”