Tools

CORS Policy Risk Checker

Flag risky CORS configurations from response headers.

CORS Policy Risk Checker

Review CORS headers to identify patterns that can expose user data across origins. This helps teams quickly sanity-check API responses and browser-facing endpoints.

How to use the CORS Policy Risk Checker

  1. Paste the CORS-related headers.
  2. Click Check.
  3. Review the risk summary.

Common use cases

  • Auditing API responses for unsafe CORS.
  • Validating CDN or proxy header changes.
  • Reviewing third-party integrations.
  • Troubleshooting browser CORS errors.

Tips & notes

  • Prefer explicit allowed origins over *.
  • Avoid credentials with wildcard origins.
  • Test behavior in the browser after changes.

Related security tools

  • HTTP Security Headers Diff Tool
  • CSP Header Tool
  • Cookie Security Flag Analyzer

FAQ

Why is wildcard risky?
It can allow any origin to access credentials.
Does this validate full CORS config?
It checks only the most common risk signals.
Does it parse preflight settings?
It focuses on headers rather than full preflight behavior.