CVE-2026-53946

Ghost: Mobiledoc image-size fetch SSRF

Vulnerable versions

This vulnerability is present in Ghost from v6.19.3 up to v6.21.0.

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 [email protected].

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.

Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside. Typical impact: access to internal metadata services, internal APIs, or cloud credentials.

CVE-2026-53946 has a CVSS score of 5.4 (Medium). The vector is network-reachable, low privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (6.21.2); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

v6.21.1 contains a fix for this issue.

1. What is CVE-2026-53946? CVE-2026-53946 is a medium-severity server-side request forgery (SSRF) vulnerability in ghost (npm), affecting versions >= 6.19.4, < 6.21.1. It is fixed in 6.21.2. Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside.
2. How severe is CVE-2026-53946? CVE-2026-53946 has a CVSS score of 5.4 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of ghost are affected by CVE-2026-53946? ghost (npm) versions >= 6.19.4, < 6.21.1 is affected.
4. Is there a fix for CVE-2026-53946? Yes. CVE-2026-53946 is fixed in 6.21.2. Upgrade to this version or later.
5. Is CVE-2026-53946 exploitable, and should I be worried? Whether CVE-2026-53946 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-53946 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-53946? Upgrade ghost to 6.21.2 or later.

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