File Upload Vulnerability in TYPO3 CMS by TYPO3
CVE-2026-15305

6.3MEDIUM

Key Information:

Vendor

Typo3

Status
Typo3 Cms
Vendor
CVE Published:
14 July 2026

What is CVE-2026-15305?

A vulnerability exists in TYPO3 CMS versions 14.2.0 to 14.3.5 that allows users to upload files with arbitrary MIME types via FileUpload or ImageUpload elements. The intended MIME type restrictions are bypassed because the MimeTypeValidator is registered during the form building process but is not applied properly in the server-side processing pipeline. This misconfiguration creates risks that unauthorized file types can be uploaded, potentially leading to further exploitation of the web application.

Affected Version(s)

TYPO3 CMS 14.2.0 < 14.3.5

References

https://typo3.org/security/advisory/typo3-core-sa-2026-020
vendor-advisory

CVSS V4

Score:
6.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Josua Vogel
Oliver Hader
.