Chainguard on October 14, 2026 introduced Chainguard Harness, an offering that uses Anthropic’s Claude Mythos 5.1 to hunt exploitable vulnerabilities in a live, isolated build of an organization’s application and deliver each verified finding with a recommended fix. The company opened a beta waitlist the same day and made the offering purchasable through the Claude Marketplace by Anthropic. In its announcement, Chainguard said frontier models that perform vulnerability discovery across…