BIT-ghost-2026-53943Published

Ghost: Cache-poisoning XSS in Ghost frontend via x-ghost-preview header

Collected exploitation and prediction evidence

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

cve-program · CVE-2026-53943

Published

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.

Source published: 24 Jun 2026 18:13:04 UTC
Source modified: 24 Jun 2026 18:48:56 UTC
Observed here: 23 Oct 2026 15:48:27 UTC
Source terms: CVE Program Terms of Use

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CVSS 3.1 · 9.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

euvd · EUVD-2026-39027

Published

EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.

Original publisher date fields

datePublished: Jun 24, 2026, 6:13:04 PM

dateUpdated: Jun 24, 2026, 6:48:56 PM

Source published: Jun 24, 2026, 6:13:04 PM (timezone not stated)
Source modified: Jun 24, 2026, 6:48:56 PM (timezone not stated)
Observed here: 7 Nov 2026 12:27:58 UTC
Source terms: ENISA EUVD · source terms and attribution apply

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EUVD CVSS 3.1 · 9.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

nvd · CVE-2026-53943

Published

NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Deferred

Weakness classifications: CWE-524

Original publisher date fields

published: 2026-06-24T19:17:11.820

lastModified: 2026-10-25T22:10:00.150

Source published: 24 Jun 2026 19:17:11 UTC
Source modified: 25 Oct 2026 22:10:00 UTC
Observed here: 27 Oct 2026 14:13:29 UTC
Source terms: NIST NVD usage terms; underlying source attribution retained

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CVSS 3.1 · [email protected] · Secondary · 9.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

osv · GHSA-62q6-4hv4-vjrw

Published

### Impact When Ghost is behind a shared caching layer that results in cached content being shared between different visitors (e.g., Fastly, Cloudflare, nginx proxy_cache, and others), 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. ### Vulnerable versions This vulnerability is present in Ghost from v4.0 up to v6.36.0. ### Patches v6.37.0 contains a fix for this issue. ### How to update For self-hosters using Docker, find [Docker's official Ghost image here](https://hub.docker.com/_/ghost). Updating a Docker-based Ghost instance [is documented here](https://docs.ghost.org/install/docker#updating-ghost). If your Ghost is a Ghost-CLI install see our documentation on [updating it to the latest version here](https://docs.ghost.org/update). If you suspect a credential compromise, use the “Reset all authentication” dialogue under Settings / Danger Zone. This is available starting with Ghost v6.41.0. ### Workarounds At the caching layer, bypass the cache for `x-ghost-preview` requests. ### References Ghost thanks [CryptoCat](https://linkedin.com/in/cryptocat) for disclosing this vulnerability responsibly. ### For more information If you have any questions or comments about this advisory, email us at [[email protected]](mailto:[email protected]).

Source published: 1 Jul 2026 21:58:32 UTC
Source modified: 1 Jul 2026 22:26:11 UTC
Observed here: 24 Oct 2026 13:17:17 UTC
Source terms: GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Publisher rating · CRITICAL