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Medium

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

  • Disclosed: 04.08.2026
  • Updated: 11.10.2026 10:22

Impact

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.

Vulnerable versions

This vulnerability is present in Ghost from v6.0.9 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.

References

Ghost thanks l3tchupkt for disclosing this vulnerability responsibly.

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.

PlatformPackageVulnerable versionsFixed in
npm package ghost >= 6.0.9, < 6.21.1 6.21.1

References

CVSS score 5.8/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Weakness (CWE)
CWE-184, CWE-918
Platform
npm
Package
ghost
Disclosed
04.08.2026
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-wvp2-4qqp-4h3r - 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.

All (61) in the archive
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

Severity:
  1. Ghost: Remote Code Execution via Bookmark Card Images
    High · 8.8 CVE-2026-105642 >= 6.56.0, < 6.67.0 6.67.0
  2. Ghost: Stored XSS via Embed Card Previews
    High · 7.3 CVE-2026-105643 >= 6.34.0, < 6.67.0 6.67.0
  3. Ghost: Stored XSS via SVG Uploads Bypassing Sanitization
    High · 7.3 CVE-2026-105649 >= 4.22.0, < 6.65.0 6.65.0
  4. Ghost: Stored XSS via oEmbed Photo Responses
    High · 8.1 CVE-2026-104414 >= 2.5.0, < 6.64.0 6.64.0
  5. Ghost: Stored XSS via Bookmark Card Images
    High · 7.3 CVE-2026-104413 >= 5.94.0, < 6.64.0 6.64.0
  6. Ghost: Invite Token Disclosure in Ghost Admin API
    High · 7.5 CVE-2026-104416 >= 4.39.0, < 6.64.0 6.64.0
  7. Ghost: Remote Code Execution via Theme Translation Files
    High · 7.2 CVE-2026-104418 >= 6.10.3, < 6.64.0 6.64.0
  8. Ghost: Stored XSS via File Uploads on Local Storage
    High · 7.3 CVE-2026-104411 >= 6.22.1, < 6.64.0 6.64.0
  9. Ghost: Private IP filtering bypass to make server-side requests to internal services this entry
    Medium · 5.8 CVE-2026-53944 >= 6.0.9, < 6.21.1 6.21.1
  10. Ghost: Cache-poisoning XSS in Ghost frontend via x-ghost-preview header
    Critical · 9.6 CVE-2026-53943 >= 4.0.0, < 6.37.0 6.37.0
  11. Ghost has incomplete CSRF protections around OTC use
    High · 7.5 CVE-2026-29784 >= 5.101.6, < 6.19.3 6.19.3
  12. Ghost Vulnerable to Remote Code Execution via Malicious Themes
    High · 7.6 CVE-2026-29053 >= 0.7.2, < 6.19.1 6.19.1
  13. Ghost has a SQL injection in Content API
    Critical · 9.4 CVE-2026-26980 >= 3.24.0, < 6.19.1 6.19.1
  14. Ghost vulnerable to XSS via malicious Portal preview links
    High · 8.8 CVE-2026-24778 >= 5.43.0, < 5.121.0, >= 6.0.0, < 6.15.0 5.121.0, 6.15.0
  15. Ghost has Staff Token permission bypass
    High · 8.1 CVE-2026-22595 >= 6.0.0, < 6.11.0, >= 5.105.0, < 5.130.6 6.11.0, 5.130.6
  16. Ghost has Staff 2FA bypass
    High · 8.1 CVE-2026-22594 >= 6.0.0, < 6.11.0, >= 5.105.0, < 5.130.6 6.11.0, 5.130.6
  17. Path Traversal in Ghost
    High · 7.5 CVE-2023-32235 < 5.42.1 5.42.1
  18. Ghost vulnerable to information disclosure of private API fields
    High · 7.5 CVE-2023-31133 < 5.46.1 5.46.1
  19. ghost vulnerable to unauthorized newsletter modification via improper access controls
    High · 8.5 CVE-2022-41654 >= 5.0.0, < 5.22.7, >= 4.46.0, < 4.48.8 5.22.7, 4.48.8
  20. Arbitrary file upload in Ghost
    Critical · 9.8 CVE-2022-27139 <= 4.39.0 no fix
  21. Arbitrary file upload in Ghost
    Critical · 9.8 CVE-2022-28397 <= 4.42.0 no fix

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