CVE-2026-53948
Ghost: File Upload Content-Type Spoofing
5.4
MEDIUM
CVSS 3.1
EPSS 0.13%
Description
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.
How to fix CVE-2026-53948
To remediate CVE-2026-53948, upgrade the affected package to a fixed version below.
- —upgrade to 6.21.1 or later
Is CVE-2026-53948 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 6.19.4, < 6.21.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |