Anthropic shuts down new AI models over security fears

Artificial intelligence giant Anthropic shut down all access to its new Fable 5 and Mythos 5 AI models after U.S. authorities sought restrictions for unspecified security concerns. The U.S. government issued an export control requiring the company to block foreign citizens’ access, Anthropic said Friday. The government cited national security authorities’ concerns without providing specific details behind the directive, according to Anthropic. However, the company said that the government apparently issued the export control after becoming aware of a potential way to bypass some safeguards on the Fable 5 AI model.

Anthropic argued that the bypass or jailbreak was minor and didn’t provide users with sufficient information to commit high-level cyberattacks. Similar vulnerabilities can be found in other publicly available AI models that don’t need a jailbreak, the company said. While Anthropic has held that the government should have authority to block unsafe AI models, its action against Fable 5 and Mythos 5 wasn’t transparent or grounded in technical facts, the company said.

Anthropic released Fable 5 on June 9, just three days before the shutdown. The AI model was the publicly available version of its top-tier Mythos model. Mythos 5 was only available for the U.S. government and some cybersecurity and infrastructure providers. While Mythos’ capabilities could lead to significant security risks in the wrong hands, Fable had strong safeguards to make it suitable for public use, the company said at the time.

What did the U.S. government say about the situation? David Sacks, a White House technology adviser, said that a highly trusted, credible partner of both Anthropic and the government found the jailbreak and believed it was a serious issue. Anthropic downplayed the issue and refused to fix it, Sacks said. The government then reluctantly issued the export control, he said.

Sacks also claimed that Anthropic had widely promoted Mythos as a cyberweapon and that any vulnerabilities in Fable risked giving bad actors access to Mythos. The Trump administration was surprised that Anthropic didn’t want to comply with safety requests that previously were a high priority, Sacks said. He added that the government wanted to lift the export control and allow Anthropic to re-release Fable 5 and Mythos 5 as soon as the issue was fixed.

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