{"action":"Upgrade @tinacms/app to 2.5.6 or later.","affected":[{"fixed":"2.5.6","introduced":"0"}],"component":"@tinacms/app","cve_ids":["CVE-2026-55660"],"ecosystem":"npm","epss":0.00279,"exploited":false,"fixed_versions":["2.5.6"],"ghsa_id":"GHSA-g5qx-h5f3-mp2f","id":"tcs_01M5KFQ8TDCKMHZDW4ZS1PS8BM","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","score":7.6},"sources":[{"source":"osv","source_id":"GHSA-g5qx-h5f3-mp2f#npm/@tinacms/app","url":"https://osv.dev/vulnerability/GHSA-g5qx-h5f3-mp2f"},{"source":"nvd","source_id":"CVE-2026-55660","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55660"}],"summary":"TinaCMS: Cross-origin postMessage handlers and rich-text URL-sanitization bypass enable stored XSS and session takeover"}