Anthropic disabled access to its Fable 5 and Mythos 5 models on June 12 after the US government issued an export control directive citing national security authorities to suspend availability for any foreign national.
The order forced Anthropic to comply immediately for all users, even though the company publicly disagrees with the underlying reasoning.
What the US Government Directive Actually Requires
An export control directive is a US government order that restricts the transfer of specific technologies to foreign nationals. In this case, the order targets Anthropic’s Fable 5 and Mythos 5 models, including access by foreign national Anthropic employees inside the country.
The company received the directive at 5:21 p.m. ET on June 12. Anthropic confirmed that to ensure full compliance, access had to be disabled for every customer, while reiterating that all other Anthropic models remain available without any disruption.
The letter did not specify the exact national security concern. However, Anthropic believes the government became aware of a method for bypassing, or “jailbreaking,” Fable 5. The company reviewed a demonstration of the technique and called it minor.
Anthropic also noted that the vulnerabilities identified appear simple. Furthermore, other publicly available models, including OpenAI’s GPT-5.5, are able to discover similar flaws without requiring any bypass at all.
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Why Anthropic Disagrees With the Federal Order
Anthropic emphasized that Fable 5 launched with stronger safeguards than any previously deployed model. Before the release, the company worked with the US government, UK AISI, and multiple third-party teams to red-team the safeguards for thousands of hours.
No tester has yet found a universal jailbreak capable of bypassing Fable 5’s protections across a wide range of cyber capabilities. As a result, Anthropic adopted a defense-in-depth approach combining narrow safeguards, monitoring, and 30-day data retention for Mythos-class models.
So far, the government has provided only verbal evidence of a narrow, non-universal jailbreak. The technique reportedly involves asking the model to read a codebase and fix software flaws, a use case widely available across the industry.
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Anthropic argued that pulling a commercial model deployed to hundreds of millions of users over a narrow vulnerability sets a problematic precedent. If applied across the industry, this standard would essentially halt all frontier AI model deployments.
The company is fully complying with the directive but has called the action a likely misunderstanding. Anthropic plans to share more technical details over the next 24 hours and is working to restore Fable 5 and Mythos 5 access as soon as possible.
The post Anthropic Suspends Access to Fable 5 and Mythos 5 After US Government Export Directive appeared first on BeInCrypto.
