{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55660","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-06-17T00:05:03.777Z","datePublished":"2026-07-01T21:00:27.321Z","dateUpdated":"2026-07-02T12:43:47.881Z"},"containers":{"cna":{"title":"TinaCMS: Cross-origin postMessage handlers and rich-text URL-sanitization bypass enable stored XSS and session takeover","problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-346","lang":"en","description":"CWE-346: Origin Validation Error","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-601","lang":"en","description":"CWE-601: URL Redirection to Untrusted Site ('Open Redirect')","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-940","lang":"en","description":"CWE-940: Improper Verification of Source of a Communication Channel","type":"CWE"}]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":7.6,"baseSeverity":"HIGH","vectorString":"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","version":"4.0"}}],"references":[{"name":"https://github.com/tinacms/tinacms/security/advisories/GHSA-g5qx-h5f3-mp2f","tags":["x_refsource_CONFIRM"],"url":"https://github.com/tinacms/tinacms/security/advisories/GHSA-g5qx-h5f3-mp2f"},{"name":"https://github.com/tinacms/tinacms/pull/7056","tags":["x_refsource_MISC"],"url":"https://github.com/tinacms/tinacms/pull/7056"}],"affected":[{"vendor":"tinacms","product":"tinacms","versions":[{"version":"< 3.9.3","status":"affected"}]},{"vendor":"tinacms","product":"@tinacms/app","versions":[{"version":"< 2.5.6","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-07-01T21:00:27.321Z"},"descriptions":[{"lang":"en","value":"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."}],"source":{"advisory":"GHSA-g5qx-h5f3-mp2f","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-02T12:43:41.136950Z","id":"CVE-2026-55660","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-07-02T12:43:47.881Z"}}]}}