Anthropic Restricts Access to New 'Claude Mythos' AI Model Over Security Concerns

US artificial intelligence (AI) startup Anthropic has built a new model it claims is too powerful to make publicly available, according to the company’s executives, as cited by several media outlets.

The firm said on Wednesday that it is discussing the model dubbed Claude Mythos Preview and its capabilities with the US government.

The news comes a month after US President Donald Trump banned government agencies from using Anthropic’s AI for six months, accusing the company of pressuring the Pentagon and endangering national security. At the time, the US Department of Defense struck a deal with the company’s rival, OpenAI, to use its tools in classified military systems.

Internal materials on the unreleased Claude Mythos model were inadvertently leaked in February after thousands of documents were left in a public data cache.

Also earlier this month, Anthropic accidentally published over 500,000 lines of secret code for its Claude AI, including unreleased features and developer notes, calling it “human error, not a security breach.”

Anthropic’s new model is “extremely autonomous” and can reason like an advanced security researcher, Logan Graham, head of the company’s frontier red team, told Axios. He said it can detect tens of thousands of vulnerabilities and, unlike previous models, generate the corresponding exploits.

In an interview with the New York Times, Graham stressed that the model marks “the starting point for what we think will be an industry change point, or reckoning, with what needs to happen now.”

In a Wednesday blog post, Anthropic said the Mythos model will be available only to a select group of tech and cybersecurity companies, citing concerns over its ability to find and exploit security flaws. The company added that it won’t be made publicly accessible until safeguards are in place to limit its most dangerous capabilities.

Rather than releasing the technology widely, Anthropic plans to provide access through a new industry partnership, Project Glasswing. The initiative, which includes over 40 organizations such as Apple, Amazon, Microsoft, Google, and NVIDIA, will test the model’s ability to identify and help fix vulnerabilities in critical software.

Anthropic said it has given the model to external groups, including US government organizations, to assess key risks – such as cybersecurity, loss of control, CBRN, and harmful manipulation – it has incorporated the findings into its overall risk assessment.