Artificial intelligence (AI) company Anthropic has disabled access to its Fable 5 and Mythos 5 models following a US government export control directive that raised national security concerns over potential vulnerabilities in the systems.
The company announced that the directive requires immediate suspension of the two models for all users, including foreign nationals and even some internal employees. Other AI models offered by Anthropic remain unaffected.
According to the company, the order was received at 5:21 pm ET and did not provide detailed technical explanations for the decision. However, US authorities reportedly cited concerns that the models could be “jailbroken,” meaning their safety controls could be bypassed under certain conditions.
Anthropic said the government shared only limited verbal details of a possible exploit involving requests to analyze and correct software code. The company stated that it had already identified and tested similar scenarios during its internal safety evaluations.
The firm emphasized that it had conducted extensive pre-release testing of the Fable 5 system in collaboration with US and UK AI safety bodies, along with other external reviewers. It argued that the alleged vulnerabilities were minor, previously known, and comparable to issues found in other widely used AI models.
Despite its disagreement with the directive, Anthropic confirmed it would comply with the government’s order while continuing discussions to restore access. The company warned that applying such strict standards broadly could significantly slow or halt the release of advanced AI systems across the industry.
Anthropic also stressed that no AI system is completely resistant to jailbreak attempts, and that all frontier models currently in use share similar safety limitations.
The decision has sparked debate in the AI industry about how governments should regulate advanced systems and balance innovation with national security concerns. Analysts say the move could signal tighter oversight of frontier AI models as they become increasingly powerful and widely deployed.