CVE-2026-53944

Ghost: Private IP filtering bypass to make server-side requests to internal services

State: Published
Severity: 5.8 Medium
Published: Jun 24, 2026
Updated: Jun 24, 2026
Reserved: Jun 11, 2026

Description

Ghost is a Node.js content management system. From 6.0.9 until 6.21.1, when making an external request, it is possible to bypass the IP filter that ensures the request isn't going to an internal service using an IPv6 literal which maps to a private IPv4 address. This vulnerability is fixed in 6.21.1.

Scores

CVSS	Score	Vector	Source
3.1	5.8 Medium	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N	GitHub_M

Weaknesses

CWE-184 Incomplete List of Disallowed Inputs
CWE-918 Server-Side Request Forgery (SSRF)

Affected Products

Product	Versions
GhostTryGhost	>= 6.0.9, < 6.21.1Affected

References

https://github.com/TryGhost/Ghost/security/advisories/GHSA-wvp2-4qqp-4h3r

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