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Squarespace fix guide

Cross-Origin Isolation Headers Not Configured on Squarespace

One or more cross-origin isolation headers (COOP, COEP, CORP) are not set. These headers provide defense-in-depth but are only required if your site uses features like SharedArrayBuffer or needs strict cross-origin isolation.

Issue ID: SEC-CROSS-ORIGIN-ISOLATION-001Severity: advisoryEffort: S

Why this matters

One or more cross-origin isolation headers (COOP, COEP, CORP) are not set. These headers provide defense-in-depth but are only required if your site uses features like SharedArrayBuffer or needs strict cross-origin isolation. This affects browser trust signals and whether visitors feel safe submitting contact details.

Squarespace fix path

How to fix this on Squarespace

Check page settings, navigation, and code injection.

  1. 1Identify whether this is page-level or site-level.
  2. 2Apply the fix.
  3. 3Republish and confirm.

After you fix it

  • ✓Confirm all three cross-origin headers are present in response headers

Same fix, other platforms

Fix cross-origin isolation headers not configured on a different CMS

Other fixes

More Squarespace fixes

Parents

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