Anthropic expands Mythos 5 access and launches $35M open source fund

Anthropic is broadening access to the cybersecurity capabilities of its advanced AI models through partner integrations, an updated Claude Security offering, a new open source funding programme, and plans to expand its Cyber Verification Program.

The move builds on Project Glasswing, launched in April, which gave a small group of organisations early access to Claude Mythos Preview and its successor, Mythos 5. Anthropic said the goal was to give defenders time to find and fix vulnerabilities before comparable capabilities became widely available or fell into the hands of malicious actors.

Claude Security, currently in public beta for Claude Enterprise customers, now runs its codebase scans on Mythos 5. Scans surface each finding with a CWE category, confidence and severity ratings, and a suggested fix. Any fix still has to be implemented through Claude Code and approved by a human before deployment.

Anthropic also launched the Defender Advantage Fund (0xDAF), putting $35 million in Claude credits toward organisations that help open source maintainers secure their projects. It follows $4 million in direct donations and other support Anthropic provided through Project Glasswing.

The Cyber Verification Program, which already gives vetted organisations reduced safeguards on Claude Opus and Sonnet for authorised security work, will expand in the coming weeks to cover broader dual-use capabilities on those models, including vulnerability triaging and validation, with Mythos-class access to follow.