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How to add Cross-Origin-Embedder-Policy on AWS CloudFront

Last updated · Reviewed by a CISSP-certified security practitioner

To add Cross-Origin-Embedder-Policy on AWS CloudFront, set the header in Response headers policy with the value require-corp. Requires embedded resources to opt in (enables cross-origin isolation). Attach the policy to the distribution's cache behavior and wait for deployment. Then confirm it with curl -I or a free FixSecurityHeaders scan.

What does Cross-Origin-Embedder-Policy do?

COEP makes the page refuse cross-origin resources that haven't opted in via CORP or CORS. Combined with COOP it enables cross-origin isolation.

Risk if missing: Informational: mainly needed for SharedArrayBuffer and high-precision timers.

What is the AWS CloudFront configuration?

Add this to Response headers policy:

Response headers policy
// aws cloudfront create-response-headers-policy --response-headers-policy-config file://policy.json
{
  "Name": "fixsecurityheaders-policy",
  "SecurityHeadersConfig": {},
  "CustomHeadersConfig": {
    "Quantity": 1,
    "Items": [
      {
        "Header": "Cross-Origin-Embedder-Policy",
        "Value": "require-corp",
        "Override": true
      }
    ]
  }
}

How do I add it step by step?

  1. Open Response headers policy.
  2. Paste the Cross-Origin-Embedder-Policy configuration shown below.
  3. Attach the policy to the distribution's cache behavior and wait for deployment.
  4. Run curl -I https://yourdomain.com and look for the cross-origin-embedder-policy line.
  5. Scan your site on FixSecurityHeaders to confirm the grade improved.

How do I verify it worked?

terminal
curl -sI https://yourdomain.com | grep -i "cross-origin-embedder-policy"
# expected:
# cross-origin-embedder-policy: require-corp

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What are the common mistakes?

  • Easily breaks third‑party images, fonts and embeds. Consider credentialless, and only deploy if you need isolation.
  • AWS provides a managed SecurityHeadersPolicy, but a custom policy lets you set CSP.
  • Enable Override so origin headers don't win.

Quick reference

HeaderCross-Origin-Embedder-Policy
Recommended valuerequire-corp
StackAWS CloudFront
WhereResponse headers policy
ComplianceOWASP ASVS V14.4

FAQ

What value should I use for Cross-Origin-Embedder-Policy?

A safe default is require-corp. Easily breaks third‑party images, fonts and embeds. Consider credentialless, and only deploy if you need isolation.

Why isn't Cross-Origin-Embedder-Policy showing up on AWS CloudFront?

AWS provides a managed SecurityHeadersPolicy, but a custom policy lets you set CSP. Also clear any CDN or page cache, and check you edited the config that actually serves your domain.

Does Cross-Origin-Embedder-Policy affect SEO or performance?

No measurable performance cost — it's a few bytes per response. It doesn't affect rankings directly, but a misconfigured policy can break page resources, so test before enforcing.

Which compliance frameworks reference Cross-Origin-Embedder-Policy?

OWASP ASVS V14.4.

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