A new Semafor report says the White House partly decided to place export restrictions on Anthropic’s Mythos over concerns that a China-linked group had accessed it.
The China concern adds a second risk: if a foreign group accessed Mythos, it might use distillation, where one model is queried repeatedly so another model can imitate its answers and capabilities.
--- semafor .com/article/06/13/2026/white-house-move-to-limit-anthropic-linked-to-concerns-about-chinese-access-to-mythos
BREAKING: The US Govt directed Anthropic to shut down its strongest Claude models.
Anthropic received the export control directive on Friday from the government. The net effect is that it must disable Fable 5 and Mythos 5 for all customers to comply.
Because, someone found a jailbreak that could make the model reveal cybersecurity help it was supposed to refuse.
Anthropic says the government has not shown a broad, universal jailbreak that turns the model into an unrestricted hacking assistant.
The shown technique was narrow, found only a small number of already known minor vulnerabilities, and produced capability that other public models can also provide.
Commerce Secretary Howard Lutnick wrote Friday that Anthropic’s Mythos 5 and Fable 5 models would face export limits anywhere outside the United States and for foreign persons within it.
The model must stay restricted until the U.S. government strengthens its national security systems, which could happen within the next few weeks.
Anthropic further said "We suspect that perfect jailbreak resistance is not currently possible for any model provider. Every safeguard used in the industry is vulnerable to non-universal jailbreaks (which can elicit some cyber information in specific circumstances), and it is likely that universal jailbreaks will eventually be found in the future."
