CVE-2025-66625
Umbraco Vulnerable to Improper File Access and Credential Exposure through Dictionary Import Functionality
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.
INFO
Published Date :
Dec. 9, 2025, 8:15 p.m.
Last Modified :
Dec. 9, 2025, 8:15 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Umbraco to version 13.12.1 or later.
- Review temporary file handling configurations.
- Monitor for unexpected file access.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-66625.
| URL | Resource |
|---|---|
| https://github.com/umbraco/Umbraco-CMS/commit/7505efd433189037f46547932d4a8b603fd4a615 | |
| https://github.com/umbraco/Umbraco-CMS/security/advisories/GHSA-hfv2-pf68-m33x |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-66625 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-66625
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-66625 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-66625 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Dec. 09, 2025
Action Type Old Value New Value 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. Added CVSS V3.1 AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-200 Added CWE CWE-552 Added CWE CWE-377 Added Reference https://github.com/umbraco/Umbraco-CMS/commit/7505efd433189037f46547932d4a8b603fd4a615 Added Reference https://github.com/umbraco/Umbraco-CMS/security/advisories/GHSA-hfv2-pf68-m33x