PT-2026-51104 · Npm · @Tinacms/App+1
Published
2026-06-19
·
Updated
2026-06-19
·
CVE-2026-55660
CVSS v4.0
8.5
High
| Vector | AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N |
TinaCMS 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. 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.
Fixed in #7056 by allow-listing trusted origins and verifying event.source (isFromAdmin, isFromTrustedPreviewOrigin), and by posting only to explicit target origins (never "*").
Note: the rich-text URL-sanitization issue previously bundled here has been split into its own advisory (GHSA-2vcc-5v34-9jc8) so each vulnerability can receive a distinct CVE.
Fix
XSS
Open Redirect
Origin Validation Error
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Related Identifiers
Affected Products
@Tinacms/App
Tinacms