CVE-2026-55660
CVE-2026-55660 · TinaCMS: Cross-origin postMessage handlers and rich-text URL-sanitization bypass enable stored XSS and session takeover
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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.
CVSS 7.6 · High · EPSS 0.3% · Fix available
- Published
- Updated
Stack: node
Affected products and versions
tinacms
- Versions
- < 3.9.3: Affected
No fix published
@tinacms/app
- Versions
- < 2.5.6: Affected
No fix published
tinacms npm
- Affected ranges
- SEMVER: < 3.9.3
Update to 3.9.3
@tinacms/app npm
- Affected ranges
- SEMVER: < 2.5.6
Update to 2.5.6