OWASP Security Skill for Claude Code

A Claude Code skill providing the latest OWASP security best practices (2025-2026) for developers building secure applications.

Quick Install

The skill is a directory (SKILL.md plus on-demand reference/ files), so install the whole folder. The easiest way is degit, which copies a GitHub subdirectory without the .git history:

npx degit agamm/claude-code-owasp/.claude/skills/owasp-security .claude/skills/owasp-security

Or install globally for all projects:

npx degit agamm/claude-code-owasp/.claude/skills/owasp-security ~/.claude/skills/owasp-security

What's Included

Claude Code Skill

Location: .claude/skills/owasp-security/

SKILL.md (the always-loaded core):

• OWASP Top 10:2025 quick reference table
• Finding-triage rubric - confirm attacker-controlled input, sink reachability, and blast radius before reporting, to cut false positives
• Security code review checklists for input handling, auth, access control, data protection, and error handling
• Secure code patterns with unsafe/safe examples
• OWASP Top 10 for LLM Applications (2025) - LLM01-LLM10 risks for chatbots, RAG, and tool-calling apps
• OWASP Agentic AI Security (2026) - ASI01-ASI10 risks for AI agent systems
• ASVS 5.0 key requirements with real 5.0 requirement IDs and levels
• Deep security analysis mindset for any language

reference/ (loaded on demand, following Claude Code progressive-disclosure best practices):

• languages.md - language-specific security quirks for 20+ languages with unsafe/safe examples
• owasp-report.md - deep-dive on the Top 10:2025, ASVS 5.0, the LLM Top 10 (2025), and the Agentic list (2026), with per-item attack vectors and mitigations

Accuracy

Category names, ASVS chapter structure, and ASVS requirement IDs and levels are verified directly against owasp.org/Top10/2025, github.com/OWASP/ASVS, and genai.owasp.org rather than paraphrased.

This matters more than it sounds: ASVS 5.0 renumbered every chapter, so 4.0 requirement IDs do not carry over, and three Top 10 categories were renamed in 2025. Much of the OWASP material circulating online still cites the old IDs and names.

Usage

Once installed, Claude Code automatically activates this skill when you:

• Review code for security vulnerabilities
• Implement authentication or authorization
• Handle user input or external data
• Work with cryptography or password storage
• Design API endpoints
• Build AI agent systems

Example Prompts

"Review this code for security issues"
"Is this authentication implementation secure?"
"What are the security risks in this Python code?"
"Help me implement secure session management"
"Check this AI agent for OWASP agentic risks"

Covered Standards

Standard	Version	Focus
OWASP Top 10	2025	Web application vulnerabilities
OWASP ASVS	5.0.0	Security verification requirements
OWASP Top 10 for LLM Apps	2025	LLM/RAG/tool-calling app risks
OWASP Agentic	2026	AI agent security risks

Language Coverage

Security quirks for 20+ languages including:

Web	Systems	Mobile	Scripting
JavaScript/TypeScript	C/C++	Swift	Python
PHP	Rust	Kotlin	Ruby
Java	Go	Dart	Perl
C#			Shell

Each language section includes common vulnerabilities, unsafe/safe code patterns, and key functions to watch for.

Alternative Installation

Clone Full Repository

git clone https://github.com/agamm/claude-code-owasp.git
cp -r claude-code-owasp/.claude/skills/owasp-security YOUR_PROJECT/.claude/skills/

Contributing

Contributions welcome! Please:

1. Fork the repository
2. Create a feature branch
3. Submit a pull request

Sources

• OWASP Top 10:2025
• OWASP ASVS 5.0 — chapter files, one per V-number
• OWASP Top 10 for LLM Applications 2025
• OWASP GenAI Security Project — home of the LLM and Agentic lists
• OWASP Cheat Sheet Series

License

MIT License - See LICENSE file for details.

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Keywords: OWASP, security, Claude Code, AI security, application security, ASVS, secure coding, vulnerability, injection, XSS, CSRF, authentication, authorization