Why is CORS validation important for my web app?

Misconfigured CORS policies can expose sensitive user data to malicious third-party sites, leading to data breaches and cross-site request forgery (CSRF) risks.

Can I validate local files or just live URLs?

Both. You can provide a path to a configuration file like cors_policy.json or a URL to a live API endpoint for real-time header analysis.

How does this skill detect CORS vulnerabilities?

It uses the cors-policy-validator plugin to compare your configuration against security best practices, flagging issues like wildcard origins in sensitive contexts or insecure header permissions.

Does this skill fix the CORS issues automatically?

The skill provides a detailed report of findings and vulnerabilities, which you can then use as a guide to update your configuration for better security.

CORS Policy Validator

Name: CORS Policy Validator
Author: jeremylongshore

byjeremylongshore

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883

Security & Testing

Analyzes and validates Cross-Origin Resource Sharing (CORS) configurations to identify security vulnerabilities and ensure compliant implementation.

About

The CORS Policy Validator skill equips Claude with the ability to audit web security settings by examining CORS headers and configuration files against industry best practices. Whether you are checking a live API endpoint or a local JSON policy file, this skill identifies misconfigurations like overly permissive wildcards or insecure origins, helping developers prevent unauthorized data access and cross-site security threats during the development and deployment phases.

Key Features

883 GitHub stars
Validation of local CORS policy configuration files (JSON/XML)
Identification of common security vulnerabilities and misconfigurations
Integration with security auditing workflows for web applications
Automated analysis of CORS headers from live API endpoints
Detailed reporting on policy correctness and security risks

Use Cases

Auditing an existing API for insecure Cross-Origin Resource Sharing settings
Validating a new CORS policy file before deploying it to production
Troubleshooting 'CORS error' issues by analyzing header responses

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add jeremylongshore/claude-code-plugins-plus-skills cors-policy-validator

For use in Claude.ai and ChatGPT

Download Skill

GitHub