CVE-2026-53943 — Ghost CMS cache poisoning via x-ghost-preview header (CVE-2026-53943)
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.4% (30-day exploitation probability)+6
- Technical severity (critical)+10
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (TryGhost Ghost).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Exploitation requires user interaction: tighten email/web filtering and warn affected users.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 9.6 | CVSS 3.1 | Critical | 2.8 | 6.0 | security-advisories@github.com via NIST National Vulnerability Database |
| 9.6 | CVSS 3.1 | Critical | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.45%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Analysis and videos
CVE-2026-53943: Ghost CMS cache poisoning via x-ghost-preview header
Ghost, the Node.js content management system, before 6.37.0 let unauthenticated users alter rendered frontend responses with an x-ghost-preview header, which a shared cache could then serve to other visitors. When the frontend and admin panel share a domain, this could lead to staff account takeover. The issue is fixed in 6.37.0 and is rated CVSS 3.1 9.6 (critical).
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · tryghost/ghost
- SSVC assessment updated
- Record published
- CVSS changed · 9.6
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
1 on the record
Elsewhere on this site
Related CVEs (same products)
- Low CVE-2026-105683 Ghost: Path Traversal Vulnerability in Ghost ImageSize Service 10d
- Low CVE-2026-105682 Ghost: Server-Side Request Forgery in Webhook Trigger 10d
- Medium CVE-2026-105681 Ghost: Authorization Bypass in Comments Feature 10d
- High CVE-2026-105679 Ghost: Stored XSS via File Uploads on Local Storage 10d
- Medium CVE-2026-105680 Ghost: Authorization Issue Allowed Author Role to Delete any Post 10d
- High CVE-2026-105675 Ghost: Invite Token Disclosure in Ghost Admin API 10d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-53943 is "Ghost CMS cache poisoning via x-ghost-preview header (CVE-2026-53943)", rated Critical. It affects Ghost (TryGhost); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.6 describes technical severity. EPSS 0.45% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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