Umbraco CMS up to 13.12.0 information disclosure

Summaryinfo

A vulnerability was found in Umbraco CMS up to 13.12.0. It has been declared as problematic. The affected element is an unknown function. Executing a manipulation can lead to information disclosure. This vulnerability is tracked as CVE-2025-66625. The attack can be launched remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Umbraco CMS up to 13.12.0. It has been declared as problematic. This vulnerability affects some unknown processing. The manipulation with an unknown input leads to a information disclosure vulnerability. The CWE definition for the vulnerability is CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. As an impact it is known to affect confidentiality. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability was named CVE-2025-66625 since 12/05/2025. The exploitation appears to be easy. The attack can be initiated remotely. Additional levels of successful authentication are required for exploitation. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1592.

Upgrading to version 13.12.1 eliminates this vulnerability. Applying the patch 7505efd433189037f46547932d4a8b603fd4a615 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Content Management System

Vendor

• Umbraco

Name

• CMS

Version

• 13.0
• 13.1
• 13.2
• 13.3
• 13.4
• 13.5
• 13.6
• 13.7
• 13.8
• 13.9
• 13.10
• 13.11
• 13.12.0

License

• open-source

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• 🔒
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CPE 2.2info

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Once again VulDB remains the best source for vulnerability data.

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