Ghost: Mobiledoc image-size fetch SSRF
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.
Summary
Ghost is a Node.js content management system. From 6.19.4 until 6.21.1, when re-rendering posts, Ghost would refetch missing image dimensions by issuing an outbound HTTP request to the URL stored on an image card — without restricting that URL to trusted image hosts. An authenticated staff user able to create or edit posts could therefore point an image card at an attacker-chosen host and cause the Ghost server to request it on their behalf, including hosts on internal networks or cloud instance metadata endpoints that would not normally be reachable from the public internet. This vulnerability is fixed in 6.21.1.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| TryGhost | Ghost | 6.19.4 to before 6.21.1 | 6.21.1 | Patch available | CNA |
| — | ghost (npm) | 6.19.4 to before 6.21.2 | 6.21.2 | Patch available | GHSA-g366-23fw-ggp6 |
- Ghost VendorTryGhost Affected 6.19.4 to before 6.21.1 Fixed in 6.21.1 Patch available CNA
- ghost (npm) Vendor— Affected 6.19.4 to before 6.21.2 Fixed in 6.21.2 Patch available GHSA-g366-23fw-ggp6
Remediation
- Fix · CNA Ghost (TryGhost) Fixed in 6.21.1
- Fix · GHSA-g366-23fw-ggp6 ghost (npm) Fixed in 6.21.2 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-53946
- 2026-10-03 Alias added: GHSA-g366-23fw-ggp6
References
More TryGhost vulnerabilities
- TI-2026-21459 Ghost has a SQL Injection in its Content API CVSS 3.1CRITICAL 9.4
- TI-2022-10277 An arbitrary file upload vulnerability in the file upload module of Ghost v4.39.0 allows… CVSS 3.1CRITICAL 9.8
- TI-2024-22785 Ghost through 5.85.1 allows remote attackers to bypass an authentication rate-limit… CVSS 3.1CRITICAL 9.1
- TI-2023-14843 Ghost vulnerable to disclosure of private API fields CVSS 3.1HIGH 7.5
- TI-2025-09049 Ghost 6.0.6 - SSRF via oEmbed Bookmark CVSS 4.0MEDIUM 6.1
- TI-2023-20918 Arbitrary file read via symlinks in Ghost CVSS 3.1MEDIUM 6.5
Sources
- CVE-2026-53946 · CVE Program
- CVE-2026-53946 · NVD
- FIRST EPSS
- GHSA-g366-23fw-ggp6 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences