Anthropic announced on Friday that it would suspend all access to its freshly launched Fable 5 and Mythos 5 models after receiving a direct order from the U.S. government. The directive, issued by a joint Department of Homeland Security and NSA task force, demanded an immediate ban on foreign users because of a newly uncovered jailbreak technique.

U.S. Task Force Cites Narrow Jailbreak in Fable 5 and Mythos 5

The security team identified a method that exploits a subtle loophole in the models' training data, allowing a crafted code prompt to override built‑in guardrails . According to sources familiar with the matter, the vulnerability is “narrow and non‑universal,” meaning it cannot be easily reproduced with other prompts, yet officials deemed it serious enough to trigger an emergency restriction.

Anthropic’s Global Suspension Affects Hundreds of Millions

In compliance with the legal mandate, Anthropic blocked access for every user, regardless of nationality, effectively cutting off businesses, researchers and developers worldwide. The company clarified that older Claude models—including Claude 3.5 and Claude 4—remain available, but the two newest releases are offline until further notice.

Previous Government‑Anthropic Clash Over Military AI Use

This is not the first time Anthropic has run afoul of U.S. regulators. earlier in the year, the startup refused the Pentagon’s request for unrestricted model access for weapons development, arguing that such use conflicted with its responsible‑AI principles. The latest order revives a broader debate about how aggressively the government should intervene in commercial AI deployments.

Industry Split: Safety First or Innovation Stifled?

Some observers applaud the government’s preemptive stance, warning that even a single exploitable flaw could enable malicious actors to weaponize advanced language models.. Others argue the move sets a dangerous precedent that could halt future frontier‑model releases and push AI research abroad. As the article notes, “If this standard was applied across the industry,we believe it would essentiaally halt all recent model deployments for all frontier model providers.”

Open Question: Will Anthropic Challenge the Order in Court?

The company has hinted at exploring legal avenues to contest the directive, but no formal lawsuit has been filed yet. What remains unclear is how long the suspension will last and whether the government will require a patched version before lifting the ban.