Vulnerability · Published Jun 24, 2026 · Assigned by GitHub_M
CVE-2026-53943Ghost: Cache-poisoning XSS in Ghost frontend via x-ghost-preview header
Critical 9.6
In plain English
A critical-severity security flaw in Ghost from TryGhost. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | ghost | 6.37.0 | GHSA-62q6-4hv4-vjrw |
Affected products (as reported)
Weakness: CWE-524 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
References
- https://github.com/TryGhost/Ghost/security/advisories/GHSA-62q6-4hv4-vjrw x_refsource_CONFIRM