Ghost: Mobiledoc image-size fetch SSRF
Impact
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.
Vulnerable versions
This vulnerability is present in Ghost from v6.19.3 up to v6.21.0.
Patches
v6.21.1 contains a fix for this issue.
How to update
For self-hosters using Docker, find Docker's official Ghost image here. Updating a Docker-based Ghost instance is documented here.
If your Ghost is a Ghost-CLI install see our documentation on updating it to the latest version here.
For more information
If you have any questions or comments about this advisory, email us at security@ghost.org.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | ghost | >= 6.19.4, < 6.21.2 | 6.21.2 |
References
- https://github.com/TryGhost/Ghost/security/advisories/GHSA-g366-23fw-ggp6
- https://nvd.nist.gov/vuln/detail/CVE-2026-53946
- https://github.com/TryGhost/Ghost/pull/26753
- https://github.com/TryGhost/Ghost/commit/ba692df7f27162d0440d57487f16c530416a8eb2
- https://github.com/TryGhost/Ghost
- https://github.com/TryGhost/Ghost/releases/tag/v6.21.1
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N- Weakness (CWE)
CWE-918- Platform
- npm
- Package
ghost- Disclosed
- 04.08.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-g366-23fw-ggp6 - CC BY 4.0
Vulnerability history: ghost
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 61
- First → latest
- 04.2021 10.2026
- Without a fix
- 3
- Exploited in attacks
- 0
Severity breakdown
- Critical 4
- High 16
- Medium 38
- Low 3
Disclosures per year
- 2021: 5
- 2022: 4
- 2023: 3
- 2024: 3
- 2025: 1
- 2026: 45
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Ghost: Mobiledoc image-size fetch SSRF this entry
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