CVE-2026-53948 — Ghost: File Upload Content-Type Spoofing

Description (CNA)

Ghost is a Node.js content management system. From 6.19.4 until 6.21.1, insufficient validation of the client-supplied Content-Type on Ghost's Admin API file upload endpoint allowed uploaded files to be served from the site with an attacker-chosen content type on S3/GCS storage backends. On installations that serve uploaded files from the same origin as the site, this could have been used to facilitate stored cross-site scripting against site visitors or staff. This vulnerability is fixed in 6.21.1.

Affected (CNA)

Vendor / product	Versions
TryGhost / Ghost	affected >= 6.19.4, < 6.21.1

CWE

CWE-434

References

https://github.com/TryGhost/Ghost/security/advisories/GHSA-944x-pm95-3jpr

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.