On Friday evening, the government issued an order directing Anthropic to block access to its Fable 5 and Mythos 5 models for all foreign nations, both within and outside the United States, citing national security concerns. The order also applied to Anthropic's own employees. In compliance, the company has completely severed access to these models for all customers.
Anthropic Responds to Government Directive
In a formal statement, Anthropic acknowledged it is adhering to the government's demands but noted that authorities “did not provide specific details of its national security concern.” The company claimed that any evidence of a potential jailbreak was conveyed verbally, and that the vulnerabilities identified were minor and could be replicated through other models, including GPT 5.5.
Steps Taken to Safeguard Models
Anthropic outlined several measures it had implemented to protect Fable and Mythos, including collaboration with the US and UK governments and revisions to its data retention policy to better track malicious usage attempts. The company emphasized that it had not received disclosure of a concerning non-universal potential jailbreak that led to harmful outcomes. According to Anthropic, the potential jailbreaks disclosed to them were either entirely benign or represented minor findings with no specific advantage for Mythos.
Despite the lack of detailed evidence, Anthropic has complied fully with the order, cutting off access to the models for all users worldwide.
