Umbraco is an ASP.NET CMS. Due to unsafe handling and deletion of temporary files in versions 10.0.0 through 13.12.0, during the dictionary upload process an attacker with access to the backoffice can trigger predictable requests to temporary file paths. The application’s error responses (HTTP 500 when a file exists, 404 when it does not) allow the attacker to enumerate the existence of arbitrary files on the server’s filesystem. This vulnerability does not allow reading or writing file contents. In certain configurations, incomplete clean-up of temporary upload files may additionally expose the NTLM hash of the Windows account running the Umbraco application. This issue is fixed in version 13.12.1.
History

Tue, 09 Dec 2025 20:15:00 +0000

Type Values Removed Values Added
Description Umbraco is an ASP.NET CMS. Due to unsafe handling and deletion of temporary files in versions 10.0.0 through 13.12.0, during the dictionary upload process an attacker with access to the backoffice can trigger predictable requests to temporary file paths. The application’s error responses (HTTP 500 when a file exists, 404 when it does not) allow the attacker to enumerate the existence of arbitrary files on the server’s filesystem. This vulnerability does not allow reading or writing file contents. In certain configurations, incomplete clean-up of temporary upload files may additionally expose the NTLM hash of the Windows account running the Umbraco application. This issue is fixed in version 13.12.1.
Title Umbraco Vulnerable to Improper File Access and Credential Exposure through Dictionary Import Functionality
Weaknesses CWE-200
CWE-377
CWE-552
References
Metrics cvssV3_1

{'score': 4.9, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2025-12-09T20:09:27.054Z

Updated: 2025-12-09T20:09:27.054Z

Reserved: 2025-12-05T15:18:02.789Z

Link: CVE-2025-66625

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-12-09T20:15:55.320

Modified: 2025-12-09T20:15:55.320

Link: CVE-2025-66625

cve-icon Redhat

No data.