{"action":"Upgrade tinacms to 3.9.3 or later.","affected":[{"fixed":"3.9.3","introduced":"0"}],"component":"tinacms","cve_ids":["CVE-2026-55660"],"ecosystem":"npm","epss":0.00279,"exploited":false,"fixed_versions":["3.9.3"],"ghsa_id":"GHSA-g5qx-h5f3-mp2f","id":"tcs_01M5KFQ8KDYTC3BEM95EV4PN06","modified_at":"2026-09-10T03:50:49.428018311Z","published_at":"2026-06-19T21:15:29Z","references":["https://osv.dev/vulnerability/GHSA-g5qx-h5f3-mp2f","https://github.com/tinacms/tinacms/security/advisories/GHSA-g5qx-h5f3-mp2f","https://github.com/tinacms/tinacms/pull/7056","https://github.com/tinacms/tinacms"],"severity":{"label":"high"},"sources":[{"source":"osv","source_id":"GHSA-g5qx-h5f3-mp2f","url":"https://osv.dev/vulnerability/GHSA-g5qx-h5f3-mp2f"}],"summary":"TinaCMS: Cross-origin postMessage handlers and rich-text URL-sanitization bypass enable stored XSS and session takeover"}