{"id":"CVE-2026-53944","aliases":["BIT-ghost-2026-53944","GHSA-wvp2-4qqp-4h3r"],"url":"https://o3.security/vulnerability/CVE-2026-53944","summary":"Ghost: Private IP filtering bypass to make server-side requests to internal services","details":"### Impact\n\nWhen 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.\n\n### Vulnerable versions\n\nThis vulnerability is present in Ghost from v6.0.9 up to v6.21.0.\n\n### Patches\n\nv6.21.1 contains a fix for this issue.\n\n### How to update\n\nFor self-hosters using Docker, find [Docker's official Ghost image here](https://hub.docker.com/_/ghost). Updating a Docker-based Ghost instance [is documented here](https://docs.ghost.org/install/docker#updating-ghost). \n\nIf your Ghost is a Ghost-CLI install see our documentation on [updating it to the latest version here](https://docs.ghost.org/update). \n\n### References\n\nGhost thanks [l3tchupkt](http://github.com/l3tchupkt) for disclosing this vulnerability responsibly.\n\n### For more information\n\nIf you have any questions or comments about this advisory, email us at [security@ghost.org](mailto:security@ghost.org).","published":"2026-06-24T18:10:30.985Z","modified":"2026-10-28T02:31:03.134829890Z","cvss":{"score":5.8,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"ghost","fixedVersion":"6.21.1"}],"fix":{"url":"https://github.com/TryGhost/Ghost/pull/26749","label":"TryGhost/Ghost#26749"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53944.json"},{"type":"ADVISORY","url":"https://github.com/TryGhost/Ghost/security/advisories/GHSA-wvp2-4qqp-4h3r"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53944"},{"type":"WEB","url":"https://github.com/TryGhost/Ghost/pull/26749"},{"type":"WEB","url":"https://github.com/TryGhost/Ghost/commit/9b7f2212970fade08ecbec543b405190471e38d4"},{"type":"PACKAGE","url":"https://github.com/TryGhost/Ghost"},{"type":"WEB","url":"https://github.com/TryGhost/Ghost/releases/tag/v6.21.1"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T02:31:03.134829890Z"}}