Why is CORS validation important for security?

Misconfigured CORS policies can allow malicious websites to make unauthorized requests to your API, potentially leading to data theft or session hijacking.

How does the reporting work?

The skill generates a detailed report summarizing the current configuration and explicitly highlighting any risks, such as wildcards in sensitive origins.

Can this skill check live API endpoints?

Yes, it can fetch and analyze CORS headers directly from a specified URL to ensure the live environment is correctly configured.

Does it support local configuration files?

Yes, Claude can read and validate local files like `cors_policy.json` or server configuration snippets to find issues before they are deployed.

What is the primary purpose of the CORS Policy Validator skill?

It identifies security vulnerabilities and misconfigurations in CORS policies for web applications and APIs to prevent unauthorized data access.

CORS Policy Validator

Name: CORS Policy Validator
Author: jeremylongshore

byjeremylongshore

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884

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Security & Testing

Analyzes and validates Cross-Origin Resource Sharing (CORS) configurations to identify security vulnerabilities and ensure compliance with best practices.

This skill enables Claude to perform deep inspections of CORS policies, whether stored in configuration files or active on live API endpoints. By leveraging the cors-policy-validator plugin, it detects common misconfigurations like overly permissive origins, credential exposure, and improper header usage, providing developers with actionable reports to secure their web applications against unauthorized cross-origin access and data leakage.

Key Features

01Heuristic analysis to identify subtle implementation flaws

02884 GitHub stars

03Detailed vulnerability reporting and security risk assessments

04Benchmarking against industry-standard security best practices

05Validation of static CORS configuration files and JSON policies

06Automated CORS header analysis for live API endpoints

Use Cases

01Troubleshooting cross-origin request failures during frontend-backend integration

02Auditing API endpoints for insecure CORS headers before production deployment

03Reviewing cloud infrastructure security policies for web-facing services

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add jeremylongshore/claude-code-plugins-plus-skills skill-adapter

For use in Claude.ai and ChatGPT

Download Skill