US government directive to suspend access to Fable 5 and Mythos 5

Capybasilisk

US government directive to suspend access to Fable 5 and Mythos 5 — LessWrong

51 US government directive to suspend access to Fable 5 and Mythos 5

by Capybasilisk

13th Jun 2026

1 min read

51

This is a linkpost for https://www.anthropic.com/news/fable-mythos-access

The US government, citing national security authorities, has issued an export control 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.

We received the directive from the government today at 5:21pm (ET). The letter did not provide specific details of its national security concern. Our understanding is that the government believes it has become aware of a method of bypassing, or “jailbreaking” Fable 5. We reviewed a demonstration of this specific technique being used to identify a small number of previously known, minor vulnerabilities. These vulnerabilities all appear relatively simple, and we have found that other publicly-available models are able to discover them as well without requiring a bypass.

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US government directive to suspend access to Fable 5 and Mythos 5

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[-]cousin_it9h5217

Right. The last important battle before the end will be whether AIs are available to all (with dangers like "rogue actors") or only to the powerful (with dangers like "eternal tyranny"). Most people on LW have been in favor of the latter, which I think is catastrophically wrong.

[-]orthonormal15h144

I'd predicted earlier (though not in writing) that the DOW would find a more powerful way to strongarm Anthropic after the SCR designation failed to force compliance. (I gave as an example "revoke visas of all foreign national Anthropic employees", but this is arguably a more devastating move.)

With Anthropic's countermove disabling Fable/Mythos for the USG as well, I think further escalation from the DOW is inevitable.

[-]Mitchell_Porter15h90

Does the Dept of War issue export controls?

[-]orthonormal14h1014

Officially it came from the Department of Commerce, but you'd have to be naive not to link this to the DOW fight, especially given last week's executive order.

[-]Mitchell_Porter16m20

I feel like Anthropic is in trouble with more than one part of the administration. A number of Biden's AI policy people went to work at Anthropic. David Sacks, who is still around as co-chair of PCAST, has obviously been a long-term opponent of Anthropic, even if he sometimes also expressed grudging admiration for their supposed tactics on the All-In podcast. There could also be an intelligence community aspect. (And who is replacing Sriram Krishnan as senior advisor on AI policy?) DOW may be part of a broader anti-Anthropic coalition.

[-]Petropolitan9h10

Doesn't the Glasswing use Mythos Preview not Mythos 5?

[-]tr5tn7h20

Presumably they would have updated.

[-]Petropolitan4h30

Maybe, but a literal reading would assign Mythos Preview to "other Antropic models" and thus allow it to be used both by the US Government as well as a few non-American Glasswing partners

[-]orthonormal1h20

Good question—my money is on them pulling Mythos Preview as well (as their only point of leverage), but I'm sure we'll find out very soon.

[-]tr5tn2h10

Not disputing they might be able to fall back to it. But in the Glasswing context I would have expected them to have updated already, given the UK AISI results on The Last Ones. Just speculation of course, and I know some Glasswing partners weren’t (exclusively) using Mythos (see the Visa harness as one example) https://www.aisi.gov.uk/blog/how-fast-is-autonomous-ai-cyber-capability-advancing

[-]Tenoke12h811

has issued an export control directive to suspend all access to Fable 5 and Mythos 5 by any foreign national

This wasn't even supposed to be general which I can see sense in but only non-Americans? It's hard to hate the American government and the people who elected this administration during the most critical period in history enough. I know how that sounds but..

[-]jbash4h81

They're relying on a legal authority that only allows them to restrict non-Americans. Since Anthropic can't tell the difference anyway, the actual effect has been to shut down everybody, at least for now.

Unusually for this administration, I think they probably actually do have legal authority to do this... assuming it's up to date to cover cloud services. I'm not sure I think they should have that authority, but there it is.

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