After a 'potential jailbreak', Anthropic is shutting off access to its Mythos 5 and Fable 5 models under national security orders from the US government

Fable 5, from Anthropic
Access to Fable 5 has been blocked for now (Image credit: Anthropic)

  • Access to Mythos 5 and Fable 5 has been pulled by Anthropic
  • The move is after a directive from the US government
  • A potential jailbreak is likely the reason for the change in access

Under orders from the US government, Anthropic is pulling access to its latest Mythos 5 and Fable 5 AI models. Access to other models is not affected, and the company is working to "restore access as soon as possible".

The directive from the White House, issued at 5.21pm Eastern time, was to block access to the next-gen AI models to "any foreign national, whether inside or outside the United States, including foreign national Anthropic employees" as per Anthropic's blog post.

However, with no way of applying that rule at the moment, access has been universally pulled. While we don't have many details, Anthropic says it understands the US government is worried about a "potential jailbreak" — but one that is apparently "narrow", "non-universal", and not reason enough to pull access to the model, in Anthropic's words.

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"If this standard was applied across the industry, we believe it would essentially halt all new model deployments for all frontier model providers," Anthropic explains. "We apologize for this disruption to our customers. We believe this is a misunderstanding and are working to restore access as soon as possible."

'This has to be a joke'

Fable 5 indefinitely suspended due to national security concerns from r/ClaudeAI

Fable 5 — the more restricted, public version of the Mythos 5 AI model that Anthropic's trusted partners have — has only been out in the wild for a matter of days, and users have been busy putting it to the test. It promises a significant step up in coding, reasoning, and agentic actions, and was put through a thorough vetting process before release.

Anthropic points out that it worked closely with authorities in the US and the UK, and with multiple third-party agencies and internal teams, to get Mythos 5 and Fable 5 safe to use. Fable's safeguards are " substantially more effective than those of any previously deployed model" according to Anthropic.

Apparently, those safeguards aren't enough for now. This story is clearly going to run and run as we discover more details about exactly what kind of jailbreak has been found, but it's clear that Anthropic doesn't think it's as dangerous as the White House does.

Understandably, users aren't impressed: according to one poster it's an "absolute nightmare scenario" while another says "this has to be a joke", and there's plenty of speculation about what this means about other AI models (including those from China).


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David Nield
Freelance Contributor

Dave is a freelance tech journalist who has been writing about gadgets, apps and the web for more than two decades. Based out of Stockport, England, on TechRadar you'll find him covering news, features and reviews, particularly for phones, tablets and wearables. Working to ensure our breaking news coverage is the best in the business over weekends, David also has bylines at Gizmodo, T3, PopSci and a few other places besides, as well as being many years editing the likes of PC Explorer and The Hardware Handbook.

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