CVE-2026-53948CWE-434

Ghost: File Upload Content-Type Spoofing

Medium · published June 24, 2026

CVSS v3.1
5.4
EPSS
0%
Percentile
12.6
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
5.4 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00226 · 12.6th percentile
Weakness
CWE-434 · Unrestricted Upload of File with Dangerous Type
Published
2026-06-24T18:06Z
EPSS history
Timeline
  • 24 JUN 18:06Z
    Ghost: File Upload Content-Type Spoofing
    cvelistv5