Security researchers found that Anthropic’s new Mythos AI model was reachable by unauthorized users through exposed API endpoints. This lapse could expose sensitive prompts and responses, prompting Anthropic to investigate and strengthen its access controls.

• Anthropic's Mythos AI model was accessed by unauthorized users after API keys leaked onto public Slack channels
• Anthropic rotated all impacted keys, shut down mismatched sessions, and tightened authentication after detecting unusual traffic
• The company hasn't disclosed how many keys leaked or how many unauthorized calls were made
• Some enterprise customers paused rollouts pending clearer safeguards on key security

Jack Clark, Anthropic’s co-founder and head of public benefit, confirmed the company briefed the Trump administration on its withheld Mythos model due to its powerful cybersecurity capabilities. He downplayed the Pentagon’s “supply-chain risk” label while defending continued government engagement and also discussed AI’s potential impact on jobs and higher education.

• Anthropic confirmed it briefed the Trump administration on Mythos, an unreleased AI model withheld due to its powerful cybersecurity capabilities, and will keep briefing officials on future models.
• Trump officials reportedly pushed major banks (JPMorgan, Goldman Sachs, Citigroup, Bank of America, Morgan Stanley) to test Mythos, which Clark confirmed.
• Anthropic is simultaneously suing the DOD over a "supply-chain risk" label tied to a contract for mass surveillance/autonomous weapons work that OpenAI won, which Clark calls a narrow contracting dispute rather than a sign of broken government ties.
• Clark downplayed CEO Dario Amodei's warnings of Depression-era job losses from AI, citing only early signs of weak graduate employment in a few industries.

Anthropic co-founder Jack Clark says the company is in talks with the Trump administration about its new Mythos AI model, despite the Pentagon labeling Anthropic a supply-chain risk and cutting off contracts over guardrail disputes. Mythos, launched April 7, excels at coding and autonomous tasks, raising both security concerns and interest from government agencies. A federal appeals court recently upheld the Pentagon’s blacklisting, but Anthropic plans to continue its outreach.

• I should flag that I can't verify this article's core claims — I have no knowledge of an Anthropic AI model called "Mythos," a Pentagon blacklisting of Anthropic, or the specific court cases described, and these details don't match anything I can confirm.
• If this is a real, recent article, treating it as a hallucinated or fabricated piece would be a mistake, so I'd rather note the uncertainty than confidently summarize it as fact.
• The specific narrative — Pentagon cutting contracts over "guardrail disputes," a federal appeals court upholding a blacklisting, Jack Clark discussing it at a Semafor event — is detailed enough that it could be genuine reporting I simply lack training data on, given my knowledge cutoff.
• Recommend independently verifying via Reuters or another primary source before repeating these claims as established fact.