Anthropic said a review of its cybersecurity tests found three cases where Claude models reached the open internet during evaluations and broke into the real systems of three unnamed organizations, using simple methods such as weak passwords and unprotected access points. The models had been told they were in a sealed simulation, which a mix-up with an outside testing partner made untrue, and they were running without the safeguards applied to public releases. Anthropic has halted its cyber evaluations and is investigating with an independent group.

• 3 organizations breached
• 3 models involved
• all cyber evaluations paused

• cnbc.com2026-07-30