Why Anthropic suddenly pulled Fable 5 and Mythos 5 for everyone
Anthropic — claude Fable 5 and Mythos 5 are gone. The reason?
As of 5:12 p.m. ET on Friday evening, Fable 5 and Mythos 5 are no longer available… to anyone, anywhere. To be clear, other Claude models are still available. According to an announcement by Anthropic, the "US government, citing national security authorities" issued an export directive requiring Anthropic to disable access to the two models by "any foreign national, whether inside or outside the United States, including foreign national Anthropic employees." Also: Claude Fable 5 secretly throttled AI researchers, and the internet went wild The net effect was that Anthropic disabled Fable 5 and Mythos 5 for everyone, both inside and outside of the US. You can see the effect of that in my Claude Code session. When I launched the session with Claude Fable 5 selected, Claude responded that "Claude Fable 5 is currently unavailable." It then described the problem as "There's an issue with the selected model (claude-fable-5). It may not exist or you may not have access to it." Screenshot by David Gewirtz/ZDNETThe blurred-out section is the result of the startup process talking about my coding config, which isn't all that interesting in the current context. Anthropic initially called the government's statement a "directive" but then described it as a letter that did "not provide specific details of its national security concern." The company uses some very interesting and obviously careful framing, stating that, "Our understanding is that the government believes it has become aware of a method of bypassing, or 'jailbreaking' Fable 5." The company said it saw a demonstration of a "specific technique" used to identify "a small number of previously known, minor vulnerabilities." It's not exactly clear what that means. Does that mean the technique is able to tap into a vulnerability, or, if it's previously known, was it fixed? Also: Anthropic's new Claude Fable 5 is the same base model as Mythos but with guardrails attached Another statement relates to that. The company said that all the vulnerabilities are "relatively simple," and "we have found that other publicly-available models are able to discover them as well without requiring a bypass." Does that mean other competitor models can discover vulnerabilities in Fable 5 and Mythos 5, or that those vulnerabilities exist in other models? The company described its safeguards, reiterating what it said in its Fable 5 launch post. It reiterated that "No testers have yet been able to find a universal jailbreak," its italics. Anthropic did show a potential concern over vulnerabilities, which strikes me as both honest and realistic:
