Anthropic opens Claude Code Security preview for AI-assisted vulnerability review

Anthropic is productizing its cyberdefense work

Anthropic announced on February 20, 2026 that Claude Code Security is now available in a limited research preview on the web version of Claude Code. The company describes it as a system that scans codebases for security vulnerabilities and proposes targeted software patches for human review. Access is opening first to Enterprise and Team customers, with expedited access for maintainers of open-source repositories.

The product pitch is straightforward: security teams face more code, more vulnerabilities, and too few specialists to investigate subtle problems. Anthropic argues that traditional static analysis tools remain useful for known patterns, but often miss context-dependent weaknesses such as broken access control, business-logic flaws, and other issues that require reasoning across components rather than simple rule matching.

How the system is supposed to differ from static analysis

According to Anthropic, Claude Code Security does not just look for signatures. It reads code the way a human researcher would, tracing how components interact and how data moves through the application. That broader context is intended to help the model identify vulnerabilities that would not be obvious from isolated files or pattern-based checks.

Anthropic also says every finding goes through a multi-stage verification process before it reaches an analyst. Claude attempts to prove or disprove its own results, assigns severity and confidence ratings, and surfaces validated findings in a dashboard where teams can inspect proposed fixes. The company is explicit that nothing is applied automatically: developers still decide whether a vulnerability is real and whether a suggested patch is acceptable.

The announcement is backed by internal research claims

The preview builds on more than a year of internal cybersecurity work. Anthropic says its Frontier Red Team has tested Claude in competitive Capture-the-Flag events, worked with Pacific Northwest National Laboratory on defending critical infrastructure, and refined its vulnerability-finding and patching workflow over time. Most notably, the company says Claude Opus 4.6 helped its team find over 500 vulnerabilities in production open-source codebases, including bugs that had remained undetected for decades.

That claim is ambitious, and Anthropic says responsible disclosure and triage are still in progress. Even so, the launch matters because it represents a shift from research demonstrations toward a concrete defensive workflow that organizations can test inside existing development processes.

Why this matters now

Anthropic's framing is that AI will be used by both attackers and defenders. If models are becoming better at discovering exploitable weaknesses, then defensive teams need access to similar capabilities with verification, governance, and human approval built in. Claude Code Security is an attempt to operationalize that argument in product form rather than leaving it at the level of red-team experiments.

Source: Anthropic official announcement.