Anthropic combines its cyber access programs into three tiers that open Mythos 5.1 and lighter safeguards to vetted defenders

Anthropic announced on October 6 an expanded Cyber Verification Program (CVP) that gives qualifying security professionals access to advanced cyber capabilities and reduced blocking classifiers. Applicants can now choose among three access tiers. Each tier includes Claude Opus 5.5, Claude Sonnet 5.5, Claude Mythos 5.1 and future models. Anthropic says its generally available models, including Opus 5.5, Fable 5.1 and Sonnet 5.5, have conservative cyber safeguards that block most cyber work, because the same capabilities that help defenders find and fix vulnerabilities can also help attackers exploit them. For the past six months the company ran two separate trusted-access programs. Project Glasswing gave organizations that secure critical software access to Claude Mythos, and the original CVP gave vetted security teams reduced safeguards on Opus and Sonnet models. SecurityWeek reports that the new structure folds both into a single offering, with separate verification requirements and security controls for each tier. According to SecurityWeek, the Defense Access tier covers SOC and incident response work, malware reverse engineering, and vulnerability analysis and validation. It is open to security teams defending their own systems, critical infrastructure operators, small security firms and open source maintainers, among others. The Hacker News headlined its report with a figure of 129,000 flaws found through Glasswing. The change matters for defenders who have been blocked by default safeguards. It also shows how frontier labs are formalizing gated access to models with strong offensive capabilities.