Anthropic puts Mythos 5 behind Claude Security scanning, launches $35M Defender Advantage Fund
On Aug 22 Anthropic announced Claude Security for Enterprise scans now run on Mythos 5, billed as standard tokens with human approval gating every patch. The same post launches the $35M Defender Advantage Fund paying maintainers in Claude credits for open-source vulnerability patching.
On August 22, Anthropic announced that Claude Security for Enterprise vulnerability scanning has been upgraded to run on Claude Mythos 5 and is now in public beta for all Claude Enterprise customers. Once an admin enables the capability in the console, a developer can pick a repository from claude.ai/security and Mythos 5 will scan the code, returning CWE categories, confidence scores, severity ratings and suggested fixes. Patching happens in Claude Code on the web, and every patch must be reviewed and approved by a human before it lands.
The billing detail is the part Anthropic called out directly: Mythos 5 scans are charged as standard token usage under the existing enterprise plan with no separate add-on SKU. Claude Security itself remains in public beta for Enterprise. Anthropic explained its safety rationale, noting that the riskiest behavior occurs when a user can prompt the model directly and steer it toward harmful uses, whereas when a user only receives a specific artifact such as a patch or an alert, that risk drops sharply. Mythos 5 only runs inside Anthropic's own tools and harness; enterprises still cannot call Mythos 5 directly for interactive patching in Claude Code.
On the same day Anthropic launched the Defender Advantage Fund, abbreviated 0xDAF, a $35 million pool of Claude credits earmarked for paying open-source maintainers to patch live vulnerabilities in widely used projects. Funding criteria include patching real vulnerabilities in widely deployed projects, automating scanning and patching in ways other projects can copy, and approaches that make a project resistant to whole classes of attack rather than one bug at a time. Anthropic is starting with a small number of larger pilot grants and will name the first recipients in the coming weeks.
The Defender Advantage Fund extends Project Glasswing, which Anthropic launched on April 7 with AWS, Microsoft, Google, CrowdStrike and the Linux Foundation, carrying up to $100 million in usage credits and $4 million in direct donations including $2.5M to Alpha-Omega and OpenSSF via the Linux Foundation and $1.5M to the Apache Software Foundation. The new fund also backs coordinated fixing efforts such as Akrites and the White House's Gold Eagle initiative.