CVE-2026-53944

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.

CVSS v3.1 Score

5.8

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

EPSS — Exploit Prediction

0.0020

Probability of exploitation

0.10%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-184 CWE-184

CWE-918 Server-Side Request Forgery (SSRF)

References

Other References

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

Frequently Asked Questions

What is CVE-2026-53944? +

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. It has a CVSS v3.1 base score of 5.8 (MEDIUM).

How severe is CVE-2026-53944? +

CVE-2026-53944 has a CVSS v3.1 score of 5.8 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0020, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-53944? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-54090

File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Prior …

CVE-2025-71355

Picklescan before 0.0.25 fails to detect unsafe global functions in the Numpy library, allowing attackers to bypass static analysis and …

CVE-2024-51745 10.0

Wasmtime is a fast and secure runtime for WebAssembly. Wasmtime's filesystem sandbox implementation on Windows blocks access to special device …

CVE-2026-49869 10.0

Kestra is an open-source, event-driven orchestration platform. Prior to 1.0.45 and 1.3.21, AuthenticationFilter in Kestra OSS uses request.getPath().endsWith("/configs") to whitelist …

CVE-2026-41264 9.8

Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.0, the …

CVE-2025-71320 9.8

picklescan before 0.0.33 contains an incomplete deny-list that fails to block pydoc.locate and operator.methodcaller functions, allowing attackers to bypass security …