{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-53943: Ghost: Cache-poisoning XSS in Ghost frontend via x-ghost-preview header","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-53943","status":"final","version":"1","initial_release_date":"2026-06-24T18:13:04.114Z","current_release_date":"2026-06-24T18:48:56.416Z","revision_history":[{"date":"2026-06-24T18:13:04.114Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"Ghost is a Node.js content management system. From  until 6.37.0, when Ghost is behind a shared caching layer that results in cached content being shared between different visitors, an unauthenticated user could send an x-ghost-preview header that altered the rendered frontend response. In affected cache configurations, that response could be stored and served to subsequent visitors requesting the same page, allowing cache poisoning of request-specific preview output. When running Ghost's frontend and admin panel on the same domain this could be used to take over staff user accounts. When running these on different domains staff accounts have no exposure. This vulnerability is fixed in 6.37.0.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-53943 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-53943"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-53943"},{"category":"external","summary":"https://github.com/TryGhost/Ghost/security/advisories/GHSA-62q6-4hv4-vjrw","url":"https://github.com/TryGhost/Ghost/security/advisories/GHSA-62q6-4hv4-vjrw"}]},"product_tree":{"branches":[{"category":"vendor","name":"TryGhost","branches":[{"category":"product_name","name":"Ghost","branches":[{"category":"product_version","name":">= 4.0.0, < 6.37.0","product":{"name":"TryGhost Ghost >= 4.0.0, < 6.37.0","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:tryghost:ghost:\\>\\=_4.0.0\\,_\\<_6.37.0:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-53943","title":"Ghost: Cache-poisoning XSS in Ghost frontend via x-ghost-preview header","notes":[{"category":"description","text":"Ghost is a Node.js content management system. From  until 6.37.0, when Ghost is behind a shared caching layer that results in cached content being shared between different visitors, an unauthenticated user could send an x-ghost-preview header that altered the rendered frontend response. In affected cache configurations, that response could be stored and served to subsequent visitors requesting the same page, allowing cache poisoning of request-specific preview output. When running Ghost's frontend and admin panel on the same domain this could be used to take over staff user accounts. When running these on different domains staff accounts have no exposure. This vulnerability is fixed in 6.37.0.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1"]},"scores":[{"cvss_v3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","baseScore":9.6,"baseSeverity":"CRITICAL"},"products":["CSAFPID-1"]}],"remediations":[{"category":"none_available","details":"No fixed version is published yet. Monitor the upstream advisory.","product_ids":["CSAFPID-1"]}]}]}