Is CVE-2026-53943 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-53943 being exploited in the wild.

How severe is CVE-2026-53943?

Critical severity, with a CVSS score of 9.6, published 24 June 2026.

Which products and versions are affected?

ghost (npm) >= 4.0.0, <= 6.36.0, SEMVER:introduced=4.0.0,fixed=6.37.0.

Is there a fix for CVE-2026-53943?

Yes. ghost (npm): upgrade to 6.37.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-53943 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-53943?

Check whether you run ghost (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-53943: TryGhost Ghost cache poisoning in frontend via x-ghost-preview header

Q: Is there a fix for CVE-2026-53943?

Yes. ghost (npm): upgrade to 6.37.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-53943 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-53943?

Check whether you run ghost (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-53943 · Severity: critical · CVSS 9.6 · Published 2026-06-24

Ghost, a popular open-source publishing platform, is vulnerable to a cache poisoning attack that could allow an attacker to take over staff accounts. By sending a specially crafted request, an attacker can trick shared caching services (like Cloudflare or Fastly) into storing a malicious version of a page. Subsequent visitors, including administrators, who view the poisoned page could have their accounts compromised if the frontend and admin panel share the same domain.

Technologies: ghost (npm). Vendors: npm.

Quick answers

Is CVE-2026-53943 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-53943 being exploited in the wild.
How severe is CVE-2026-53943?: Critical severity, with a CVSS score of 9.6, published 24 June 2026.
Which products and versions are affected?: ghost (npm) >= 4.0.0, <= 6.36.0, SEMVER:introduced=4.0.0,fixed=6.37.0.
Is there a fix for CVE-2026-53943?: Yes. ghost (npm): upgrade to 6.37.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-53943 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-53943?: Check whether you run ghost (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

ghost (npm): upgrade to 6.37.0 or later
```
npm install ghost@6.37.0
```

Technical details

Ghost is vulnerable to cache poisoning leading to Cross-Site Scripting (XSS). An unauthenticated remote attacker can send a request containing a malicious 'x-ghost-preview' header; if Ghost is behind a shared caching layer (e.g., Fastly, Cloudflare, Nginx proxy_cache) that does not account for this header in its cache key, the altered response may be cached. When the frontend and admin panel share a domain, this allows for the execution of arbitrary scripts in the context of staff users, enabling account takeover. The vulnerability is present in versions 4.0.0 through 6.36.0 and is patched in version 6.37.0. A workaround involves configuring the caching layer to bypass the cache for requests containing the 'x-ghost-preview' header.

Affected products

Ghost Foundation Ghost 4.0.0 - 6.36.0

Identifiers

CVE-2026-53943
GHSA-62q6-4hv4-vjrw

Timeline

2026-05-28: disclosed: Vulnerability reported to Ghost Foundation
2026-06-24: advisory: NVD publication date
2026-07-01: advisory: GitHub Advisory published/reviewed

References

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