VULNERABILITY INTELLIGENCE

CVE-2026-53948

CVSS score5.4 MEDIUM
EPSS probability0.23%
CISA KEVNot currently listed
Published2026-06-24
Last modified2026-10-25
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

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.

Weakness classification

  • security-advisories@github.com: CWE-434

Primary references