Claude Code Security: A Developer's Guide to AI Vulnerability Scanning
How Anthropic's new security tool finds bugs that static analysis misses — and how to use it effectively.
We use Claude Code every day at Context Studios. It writes our code, reviews our PRs, and now — as of February 21, 2026 — it can scan our entire codebase for security vulnerabilities too.
Anthropic launched Claude Code Security as a limited research preview, and within 24 hours, cybersecurity stocks dropped by billions. CrowdStrike fell 7.8%. Okta dropped 9.2%. That market reaction tells you something about how seriously the industry is taking this.
But the stock market story isn't the interesting part. The interesting part is what this tool actually does, how it differs from existing security scanners, and how developers can use it to ship more secure code. This guide breaks it all down.
What Claude Code Security Actually Does
Claude Code Security is a vulnerability scanning capability built directly into Claude Code on the web. Connect it to a GitHub repository, point it at your codebase, and it scans for security issues — then suggests targeted patches for human review.
That description sounds like every other security tool on the market. The difference is in how it scans.
Traditional static analysis tools are rule-based. They match your code against a database of known vulnerability patterns. SQL injection patterns, exposed credentials, outdated encryption — if there's a rule for it, they'll catch it. According to Anthropic's official announcement on February 21, 2026, these tools "catch common issues, like exposed passwords or outdated encryption, but often miss more complex vulnerabilities, like flaws in business logic or broken access control."
Claude Code Security doesn't scan for patterns. It reads and reasons about code the way a human security researcher would. It understands how components interact, traces how data moves through your application, and catches complex vulnerabilities that rule-based tools miss.
How the Scanning Process Works
Here's the step-by-step process Claude Code Security follows when scanning your code:
Step 1: Connect Your Repository
Developers activate Claude Code Security by connecting it to a GitHub repository through the Claude Code web interface. The tool needs access to the full codebase — not just individual files — because many vulnerabilities only become visible when you understand how components interact.
Step 2: Deep Code Reasoning
Unlike static analyzers that match patterns, Claude reads your code contextually. It traces data flows across your application, understands business logic, and identifies how different components interact. This is the same approach a senior security researcher would take during a manual code review — except it operates at machine speed across the entire codebase.
According to CyberScoop's reporting on February 21, 2026, Anthropic claims Claude Code Security "reads and reasons about your code the way a human researcher would," showing an understanding of how different software components interact.
Step 3: Multi-Stage Verification
Every finding goes through a multi-stage verification process. Claude re-examines each result, attempting to prove or disprove its own findings and filter out false positives. This self-verification step is critical — false positives are one of the biggest productivity killers in security tooling.
Each vulnerability gets two ratings:
- Severity rating — how critical is this issue?
- Confidence rating — how sure is Claude that this is a real vulnerability?
The confidence rating is particularly valuable. As Anthropic notes, "these issues often involve nuances that are difficult to assess from source code alone." The confidence rating helps teams decide which findings to investigate first.
Step 4: Dashboard Review and Patching
Validated findings appear in the Claude Code Security dashboard. For each vulnerability, teams can:
- Review the identified code
- Inspect the suggested patch
- Approve or reject the fix
Nothing is applied automatically. Claude Code Security identifies problems and suggests solutions, but developers always make the final call. This human-in-the-loop approach means the tool augments your security team rather than replacing it.
What Types of Vulnerabilities Can It Find?
Based on Anthropic's research results and public documentation, Claude Code Security targets vulnerabilities across several categories:
Vulnerabilities Traditional Tools Catch Well
- Exposed credentials and API keys
- Outdated encryption algorithms
- Known CVE patterns
- Basic injection vulnerabilities
Vulnerabilities Where Claude Code Security Adds Value
- Business logic flaws — errors in how your application processes transactions, permissions, or workflows that don't match any known pattern
- Broken access control — subtle issues where authentication checks exist but can be bypassed through unexpected code paths
- Complex data flow vulnerabilities — issues that only become apparent when tracing data across multiple services and components
- Context-dependent bugs — vulnerabilities that require understanding what the code is supposed to do, not just what it does
This second category is where the tool's reasoning capability shines. Static analysis fundamentally can't catch business logic flaws because it doesn't understand business logic. Claude does — or at least, it gets close enough to find bugs that have escaped human review for years.
The Track Record: 500+ Vulnerabilities in Production Code
Claude Code Security builds on over a year of cybersecurity research from Anthropic's Frontier Red Team. The results are striking.
Using Claude Opus 4.6, released on February 5, 2026, Anthropic's team found over 500 vulnerabilities in production open-source codebases. According to Anthropic's research blog, these were "bugs that had gone undetected for decades, despite years of expert review."
The team refined Claude's capabilities through:
- Capture-the-Flag competitions — testing Claude against real security challenges
- Partnership with Pacific Northwest National Laboratory — experimenting with AI-powered defense of critical infrastructure
- Internal dogfooding — using Claude to review Anthropic's own code, which they describe as "extremely effective"
CyberScoop reported on February 21, 2026 that while AI cybersecurity capabilities have "clearly improved in recent years, they tend to be most effective at finding lower impact bugs, while experienced human operators are still needed in many organizations to manage the model and deal with higher-level threats and vulnerabilities." This is an honest assessment — Claude Code Security isn't replacing your security team, but it dramatically expands the volume of code that gets reviewed.
How to Set Up Claude Code Security
Prerequisites
- Claude Enterprise or Team plan
- GitHub repository access
- Code ownership verification (you must own or have rights to scan the code)
Getting Access
As of February 22, 2026, Claude Code Security is in limited research preview. Here's how to get in:
- Enterprise/Team customers: Apply through claude.com/contact-sales/security
- Open-source maintainers: Apply for free, expedited access through the same page
Anthropic requires that testers only use Claude Code Security on code their company owns and "holds all necessary rights to scan." Third-party code, licensed code, and open-source projects you don't maintain are off-limits during the preview.
Running Your First Scan
Once you have access:
- Open Claude Code on the web
- Connect your GitHub repository
- Ask Claude to scan your codebase for security vulnerabilities
- Review findings in the Claude Code Security dashboard
- Inspect suggested patches
- Approve fixes through your normal code review process
The tool integrates directly into Claude Code's existing workflow, so there's no separate interface to learn.
Best Practices for AI-Powered Security Scanning
Based on our experience using Claude Code daily and the patterns emerging from early Claude Code Security users, here are practical recommendations:
1. Start with Your Most Critical Codepaths
Don't scan everything at once. Begin with authentication, payment processing, and data handling code — the areas where vulnerabilities cause the most damage.
2. Pay Attention to Confidence Ratings
High severity + high confidence findings should go straight to the top of your remediation queue. High severity + low confidence findings need human review before acting — Claude might be flagging a legitimate design decision rather than a vulnerability.
3. Use It Alongside Traditional Tools
Claude Code Security isn't a replacement for your existing security stack. Use it as a complementary layer. Traditional static analysis catches the known patterns quickly and cheaply. Claude Code Security catches the things static analysis misses.
4. Review Patches Carefully
The suggested patches are starting points, not final solutions. Security fixes often have implications for functionality, performance, and other parts of the codebase. Your team should review every patch the same way you'd review any other code change.
5. Establish a Feedback Loop
When Claude Code Security misidentifies something (false positive) or misses something you find later, document it. As AI security tools improve, this kind of feedback data becomes invaluable for understanding their strengths and limitations.
What This Means for the Security Industry
The market reaction — billions wiped from cybersecurity stocks in a single day — might seem overblown. But it signals a real shift.
According to Anthropic's announcement, "We expect that a significant share of the world's code will be scanned by AI in the near future, given how effective models have become at finding long-hidden bugs and security issues."
This doesn't mean cybersecurity companies are obsolete. It means the baseline is moving up. AI-powered scanning will handle the volume of code that no human team could review. Human security researchers will focus on the complex, high-stakes work that requires judgment, context, and adversarial thinking.
For developers, the practical takeaway is simpler: the cost of NOT scanning your code for vulnerabilities just went up. If AI can find decades-old bugs in production code, and that capability is available as a point-and-click tool, the expectation that every team runs security scans will become table stakes.
The SuperClaw Factor: Red-Teaming Your AI Agents
One related development worth mentioning: Superagentic AI released SuperClaw in the same week, an open-source framework for red-teaming AI agents before deployment. As AI coding agents become more autonomous, testing their security posture becomes critical.
Claude Code Security scans your codebase. SuperClaw tests whether your AI agents themselves can be manipulated or exploited. Together, they represent two sides of the AI security coin — securing what AI produces and securing AI itself.
Getting Started Today
Claude Code Security represents a genuine step forward in making security scanning accessible. The combination of deep code reasoning, multi-stage verification, and human-in-the-loop patching addresses real gaps in existing tooling.
If you're on a Claude Enterprise or Team plan, apply for the research preview at claude.com/contact-sales/security. If you maintain open-source projects, you can get free expedited access.
For everyone else, the general availability timeline hasn't been announced yet. But the capabilities demonstrated — 500+ real vulnerabilities found in production code — suggest this tool will be worth the wait.
The security landscape is shifting. AI-powered vulnerability scanning isn't replacing human judgment — it's making sure that judgment gets applied to the problems that actually matter, instead of drowning in backlogs of unreviewed code.
Frequently Asked Questions
What is Claude Code Security?
Claude Code Security is a vulnerability scanning tool built into Claude Code on the web. Released on February 21, 2026 as a limited research preview, it scans codebases for security vulnerabilities and suggests targeted patches for human review. Unlike traditional static analysis, it uses AI reasoning to understand code context and catch complex vulnerabilities.
How is Claude Code Security different from traditional static analysis?
Traditional static analysis matches code against known vulnerability patterns — it works through rules. Claude Code Security reads and reasons about code contextually, understanding how components interact and tracing data flows. This allows it to catch business logic flaws, broken access control, and context-dependent bugs that rule-based tools miss.
Who can access Claude Code Security?
As of February 2026, it's available in a limited research preview to Claude Enterprise and Team customers. Open-source project maintainers can apply for free, expedited access. General availability timing has not been announced.
Does Claude Code Security automatically fix vulnerabilities?
No. Claude Code Security identifies vulnerabilities and suggests patches, but nothing is applied without human approval. Developers review each finding in a dashboard, inspect the suggested fix, and decide whether to approve it. This human-in-the-loop approach ensures developers maintain full control.
What vulnerabilities has Claude found so far?
Using Claude Opus 4.6, Anthropic's Frontier Red Team found over 500 vulnerabilities in production open-source codebases — including bugs that had gone undetected for decades despite years of expert review. They are currently working through responsible disclosure with affected maintainers.
Can I use Claude Code Security on any codebase?
During the research preview, users must only scan code their company owns and holds all necessary rights to scan. Third-party code, licensed code, and open-source projects you don't maintain are not permitted during the preview phase.