Anthropic on Tuesday expanded its Cyber Verification Program, letting vetted cybersecurity professionals test its most powerful models — Claude Opus 5.5, Sonnet 5.5, Mythos 5.1 and future models — with fewer safeguards. The revamped program merges the six-month-old Project Glasswing and the original CVP into a single initiative.

Glasswing's impact is the proof point: partners found at least 129,000 verified vulnerabilities between April and July, with more than 33,000 rated critical or high severity, and Anthropic says the true figure is likely at least five times higher. The program has three tiers — Defense for incident response and malware analysis, Red Team for authorized penetration testing by organizations only, and a Specialized tier with the fewest restrictions for safety-critical systems like power grids and interbank networks.

Anthropic vets each member together with the US government, and existing Glasswing members move into the Defense tier. The expansion comes after the April unveiling of Claude Mythos Preview raised fears that frontier AI could hack software before it has been secured.