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Security fix guide

Permissive CORS Configuration

The Access-Control-Allow-Origin header is set to wildcard (*) or reflects any origin, which may allow unauthorized cross-origin access to resources.

Issue ID: SEC-CORS-001
Severity: moderate
Impact: Med
Effort: S

Use this article when

  • You need deeper remediation guidance than the issue card can show.
  • You want CMS-specific steps before handing the fix to a developer.
  • You want a repeatable re-check path after shipping the change.
Re-run full audit

What this issue is

The Access-Control-Allow-Origin header is set to wildcard (*) or reflects any origin, which may allow unauthorized cross-origin access to resources.

Why it matters

The Access-Control-Allow-Origin header is set to wildcard (*) or reflects any origin, which may allow unauthorized cross-origin access to resources. This affects browser trust signals and whether visitors feel safe submitting contact details.

How we detect it

  • FreeSiteAudit flags this issue when the rule for SEC-CORS-001 fails and the page evidence points to Http headers.
  • You can usually confirm this by checking the page source or the relevant page settings inside your CMS.

Evidence examples

Check the affected page source, rendered output, or relevant CMS setting to confirm the missing or incorrect element.

How to fix it

  1. 1Restrict Access-Control-Allow-Origin to specific trusted origins
  2. 2Avoid reflecting the Origin header without validation
  3. 3Never use wildcard with credentials

How to re-check it

  • Check response headers and confirm CORS is restricted to trusted origins

Related tools

This issue is best verified with the full FreeSiteAudit crawl rather than a single-point mini tool.