Anthropic opens its most powerful AI models to more security teams

Anthropic is expanding a program that allows vetted cybersecurity professionals to test its most powerful AI models with fewer safeguards, after its Project Glasswing initiative helped uncover more than 100,000 software vulnerabilities this year.

Its partners under Glasswing, an ‌initiative aimed at securing the world's most critical software, found at least 129,000 verified vulnerabilities between April and July.

Anthropic's own open-source scanning found 5,500 more between April and October.

More than 33,000 have so far been rated critical or high severity.

Anthropic said the figures are likely an undercount and expects the true impact to be at least five times higher, as the data comes from a survey of a limited number of partners.

The revamped Cyber Verification Program (CVP) announced on Tuesday combines two programs Anthropic has run for the past six months.

The first, Glasswing, gave organizations securing critical software access to Claude Mythos, Anthropic's most cyber-capable family of models.

The second, the original CVP, gave vetted security teams reduced safeguards on Claude Opus and Sonnet models.

The company's April unveiling of Claude Mythos Preview raised fears ‌that AI could hack software before it had been secured.

The new program has three tiers, each with its own verification requirements and security controls.

All three include access to Claude Opus 5.5, Sonnet 5.5, Mythos 5.1 and future models.

The Defense tier covers work such as incident response and malware analysis.

Security teams, critical infrastructure operators, open-source maintainers and researchers with a record of reported vulnerabilities can apply.

The Red Team tier adds authorized penetration testing and red-teaming, but only organizations can apply.