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TI-2026-38916 Aliases CVE-2026-53948GHSA-944x-pm95-3jpr

Ghost: File Upload Content-Type Spoofing

Priority LOW 24CWE-434Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
Required
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
Low · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-434.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00226 13th percentileScored 2026-11-07
Fix Fixed Ghost (TryGhost): 6.21.1ghost (npm): 6.21.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
TryGhostGhost6.19.4 to before 6.21.16.21.1Patch availableCNA
—ghost (npm)6.19.4 to before 6.21.16.21.1Patch availableGHSA-944x-pm95-3jpr
  • Ghost VendorTryGhost Affected 6.19.4 to before 6.21.1 Fixed in 6.21.1 Patch available CNA
  • ghost (npm) Vendor— Affected 6.19.4 to before 6.21.1 Fixed in 6.21.1 Patch available GHSA-944x-pm95-3jpr

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:ghost:ghost:*:*:*:*:*:*:*:*——TryGhost
  • cpe:2.3:a:ghost:ghost:*:*:*:*:*:*:*:* Versions — — ·TryGhost

Remediation

  • Fix · CNA Ghost (TryGhost) Fixed in 6.21.1
  • Fix · GHSA-944x-pm95-3jpr ghost (npm) Fixed in 6.21.1 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-53948
  2. 2026-10-03 Alias added: GHSA-944x-pm95-3jpr

References

Advisory 1

Other 5

  • TI-2026-21459 Ghost has a SQL Injection in its Content API CVSS 3.1CRITICAL 9.4
  • TI-2022-10277 An arbitrary file upload vulnerability in the file upload module of Ghost v4.39.0 allows… CVSS 3.1CRITICAL 9.8
  • TI-2024-22785 Ghost through 5.85.1 allows remote attackers to bypass an authentication rate-limit… CVSS 3.1CRITICAL 9.1
  • TI-2023-14843 Ghost vulnerable to disclosure of private API fields CVSS 3.1HIGH 7.5
  • TI-2025-09049 Ghost 6.0.6 - SSRF via oEmbed Bookmark CVSS 4.0MEDIUM 6.1
  • TI-2023-20918 Arbitrary file read via symlinks in Ghost CVSS 3.1MEDIUM 6.5
See all 109 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences