Anthropic received a US government export control directive to suspend access to Fable 5 and Mythos 5 models due to a reported narrow jailbreak enabling the models to analyze software vulnerabilities. The government did not provide detailed national security concerns but cited this capability as the reason. Anthropic reviewed the jailbreak, finding it limited and comparable to capabilities in other publicly available models. They emphasize their defense-in-depth safeguards and monitoring, noting no universal jailbreak has been found. The directive requires disabling access for all users, including foreign nationals and employees, despite Anthropic's disagreement with the decision and its potential industry-wide impact.

Access to Anthropic's Fable 5 and Mythos 5 models has been suspended for all users to comply with the US government directive. This disrupts customers relying on these models but does not affect other Anthropic models. The directive stems from concerns about a narrow jailbreak that enables vulnerability analysis, though this capability exists in other AI models. The suspension may set a precedent affecting future frontier AI model deployments. There is no evidence of exploitation in the wild or harmful outcomes from the jailbreak so far.

Anthropic is complying with the government directive by disabling access to Fable 5 and Mythos 5 for all users. No further action is required by customers at this time. Anthropic continues to monitor and research jailbreaks and aims to restore access once compliance and safety concerns are addressed. Customers should follow official communications from Anthropic for updates.