Anthropic expands its Cyber Verification Program into three tiers, with a top tier for testing power grids and interbank systems

Anthropic launched an expanded Cyber Verification Program on 6 October, which gives qualifying security professionals advanced cyber capabilities and fewer blocking classifiers. It now has three access tiers and covers Claude Opus 5.5, Claude Sonnet 5.5 and Claude Mythos 5.1, “and new models moving forward”.

Defense Access is for work such as incident response and malware analysis, and individual researchers with a track record of reported vulnerabilities can qualify. Red Team Access is for authorised penetration testing; “Currently, this tier is for organizations only; individual researchers are not eligible.” Specialized Access is reserved for a limited set of verified organisations authorised to test systems “such as flight operating systems, power grids, telecom networks, interbank transfer infrastructure, and government administrative networks.”

Anthropic gives its own numbers for the work so far: partners uncovered “at least 129,000 verified software vulnerabilities between April and July 2026”, its own scanning found another 5,500 between April and October 2026, and more than 33,000 have so far been rated critical or high severity.

The move follows Google's decision, reported here on 1 October, to give Gemini 4 Argon to vetted cyber defenders first with its cyber guardrails off. On the same day as Anthropic's post, Mistral said state authorities and cybersecurity firms are red-teaming Large 4 with reduced moderation.

• Confirmed Three tiers (Defense, Red Team, Specialized) launched 6 October, covering Claude Opus 5.5, Sonnet 5.5 and Mythos 5.1. Anthropic
• Claimed Partners found at least 129,000 verified vulnerabilities from April to July 2026, Anthropic's own scanning 5,500 more, and over 33,000 are rated critical or high. Anthropic
• Confirmed Red Team Access is for organisations only; individual researchers with a record of reported vulnerabilities can qualify for Defense Access. Anthropic