CVE-2025-66625

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

MEDIUM
4.9
CVSS Score
Published: December 9, 2025 at 08:09 PM UTC
Updated: October 14, 2026 at 09:10 PM UTC
1 product affected across 1 vendorUmbraco-CMS

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Severity
MEDIUM4.9
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

10.0.0 ≤ v < 13.12.1
Affected range stops below 13.12.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.9MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-200CWE-377CWE-552

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