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.
References (1)
Core 1
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/TryGhost/Ghost/security/advisories/GHSA-944x-pm95-3jpr
Scores
CVSS v3
5.4
EPSS
0.0013
EPSS Percentile
3.2%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-434
Status
published
Products (1)
TryGhost/Ghost
>= 6.19.4, < 6.21.1
Published
Jun 24, 2026
Tracked Since
Jun 25, 2026