CVE-2025-66625

Umbraco Vulnerable to Improper File Access and Credential Exposure through Dictionary Import Functionality

State: Published
Severity: 4.9 Medium
Published: Dec 9, 2025
Updated: Dec 12, 2025
Reserved: Dec 5, 2025

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.

Scores

CVSS	Score	Vector	Source
3.1	4.9 Medium	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N	GitHub_M

Weaknesses

CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
CWE-377 Insecure Temporary File
CWE-552 Files or Directories Accessible to External Parties

Affected Products

Product	Versions
Umbraco-CMSumbraco	10.0.0, < 13.12.1Affected

References

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