Vulnerability Description
Tina is a headless content management system. In versions prior to @tinacms/app 2.5.6 and tinacms 3.9.3, cross-origin postMessage handlers and a rich-text URL-sanitization bypass enable stored XSS and session takeover. The library registers window message listeners — the useTina overlay handler, the OAuth authentication popup handler, and the admin↔preview iframe GraphQL reducer — that act on event.data without verifying event.origin or event.source and post messages using non-specific target origins, while insufficient URL sanitization in rich-text content allows malicious URLs to persist and execute. A page the victim visits (or a window in an opener/iframe relationship with a Tina admin) can forge messages to drive the editor, inject preview content, or observe/forge the OAuth popup channel to take over an authenticated editing session. This issue has been fixed in versions @tinacms/app 2.5.6 and tinacms 3.9.3.
Related Weaknesses (CWE)
References
- https://github.com/tinacms/tinacms/pull/7056
- https://github.com/tinacms/tinacms/security/advisories/GHSA-g5qx-h5f3-mp2f
FAQ
What is CVE-2026-55660?
CVE-2026-55660 is a documented vulnerability. Tina is a headless content management system. In versions prior to @tinacms/app 2.5.6 and tinacms 3.9.3, cross-origin postMessage handlers and a rich-text URL-sanitization bypass enable stored XSS and...
How severe is CVE-2026-55660?
CVSS scoring is not yet available for CVE-2026-55660. Check NVD for updates.
Is there a patch for CVE-2026-55660?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.