Anthropic Suspends Fable 5, Mythos 5 AI Models Globally Following US Govt Directive

• US ordered Anthropic to suspend all access to Fable 5 and Mythos 5 for any foreign national inside or outside the United States, including foreign Anthropic employees

• India is Anthropic's second-largest market with TCS deal for 50,000 employees and Infosys collaboration for enterprise AI solutions using Claude models

• Anthropic termed the government action a "misunderstanding," arguing the jailbreak is "narrow, non-universal" and working to restore access as soon as possible

Artificial intelligence major Anthropic has abruptly suspended access to its advanced AI models, Fable 5 and Mythos 5, for all customers globally following an export control directive from the US government citing national security concerns.

According to the company's statement, the US government issued the directive to suspend all access to Fable 5 and Mythos 5 by any foreign national, whether inside or outside the United States, including foreign national Anthropic employees.

"The net effect of this order is that we must abruptly disable Fable 5 and Mythos 5 for all our customers to ensure compliance. Access to all other Anthropic models will not be affected," the company said.

The suspension is expected to impact Indian users and enterprises, as India is Anthropic's second-largest market.

The development follows major partnerships between the AI firm and Indian IT giants, including a recent deal with TCS to equip 50,000 employees with Anthropic's models, and a collaboration announced by Infosys in February to deploy advanced enterprise AI solutions using the Claude family of models.

Furthermore, select Indian government agencies and private firms were recently granted access to the Mythos model under a cybersecurity initiative called Project Glasswing, according to sources familiar with the matter.

The US directive follows earlier alarms raised within the Indian government regarding advanced AI models. In April, Finance Minister Nirmala Sitharaman directed banks and financial institutions to bolster their cybersecurity frameworks and coordinate with CERT-In to counter emerging AI-linked threats.

The high-level meeting was convened amid global concerns surrounding Anthropic's Claude Mythos system, which the company had withheld from public release due to its advanced ability to exploit software bugs.

Anthropic stated it received the directive from the US government at 5.21 pm (ET) on June 12. While the letter did not provide specific details regarding the national security concern, the company understands that the government believes it has become aware of a method to bypass Fable 5.

Defending its models, Anthropic said it reviewed a demonstration of the specific technique and found it to be a "narrow, non-universal jailbreak" that essentially consists of asking the model to read a specific codebase and fix software flaws.

The company argued that this level of capability is widely available from other models, including OpenAI's GPT-5.5, and is routinely used by cybersecurity defenders.

"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," Anthropic said.

The AI firm noted that perfect jailbreak resistance does not appear to be possible today and that it relies on a "defence in depth" strategy.

"This is also why Anthropic has required 30-day retention of customer data with Fable a policy change that carries real costs for us with customers, but that allows us to research and mitigate jailbreaks." Apologising to its customers for the disruption, Anthropic termed the government's action a "misunderstanding" and stated it is working to restore access as soon as possible.

"We believe the government should have the ability to block unsafe deployments, as part of a statutory process that is transparent, fair, clear, and grounded in technical facts. This action does not adhere to those principles," the statement added.