Vulnerability · Published Dec 9, 2025 · Assigned by GitHub_M
CVE-2025-66625Umbraco Vulnerable to Improper File Access and Credential Exposure through Dictionary Import Functionality
Medium 4.9
In plain English
A medium-severity information exposure in Umbraco-CMS from umbraco. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| NuGet | umbraco.cms | 13.12.1 | GHSA-hfv2-pf68-m33x |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| umbraco | Umbraco-CMS | 10.0.0, < 13.12.1 |
Weakness: CWE-200, CWE-377, CWE-552 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N