TinaCMS: Cross-origin postMessage handlers and rich-text URL-sanitization bypass enable stored XSS and session takeover (tinacms tinacms)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.28 % · percentile 20 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Deferred
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.
Weaknesses (CWE)
- CWE-79 — Improper Neutralization of Input During Web Page Generation
- CWE-346 — Origin Validation Error
- CWE-601 — URL Redirection to Untrusted Site
- CWE-940 — Improper Verification of Source of a Communication Channel
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | HIGH 7.6 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N | GitHub_M |
| CVSS 4.0 | HIGH 7.6 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD · security-advisories@github.com (Secondary) |
Advisories
- GHSA-g5qx-h5f3-mp2f — TinaCMS: Cross-origin postMessage handlers and rich-text URL-sanitization bypass enable stored XSS and session takeover
European references
- ENISA EUVD · EUVD-2026-41143
- GCVE · GCVE-0-2026-55660
Affected products
| Product | Versions |
|---|---|
| tinacms · tinacms | affected < 3.9.3 |
| tinacms · @tinacms/app | affected < 2.5.6 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |