EUVD-2025-16778
GHSA-fr6r-p8hv-x3c4
CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:L
Lifecycle Timeline
4Tags
Description
Umbraco is an ASP.NET content management system (CMS). Starting in version 14.0.0 and prior to versions 15.4.2 and 16.0.0, it's possible to upload a file that doesn't adhere with the configured allowable file extensions via a manipulated API request. The issue is patched in versions 15.4.2 and 16.0.0. No known workarounds are available.
Analysis
Umbraco is an ASP.NET content management system (CMS). Starting in version 14.0.0 and prior to versions 15.4.2 and 16.0.0, it's possible to upload a file that doesn't adhere with the configured allowable file extensions via a manipulated API request. The issue is patched in versions 15.4.2 and 16.0.0. No known workarounds are available.
Technical Context
Unrestricted file upload allows attackers to upload malicious files (web shells, executables) that can then be executed on the server. This vulnerability is classified as Unrestricted Upload of File with Dangerous Type (CWE-434).
Affected Products
Affected products: Umbraco Umbraco Cms
Remediation
A vendor patch is available — apply it immediately. Validate file types by content (magic bytes), not just extension. Store uploads outside the web root. Use random filenames. Scan uploads for malware.
Priority Score
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External POC / Exploit Code
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