CVE-2025-46736: Umbraco.Cms Umbraco Makes User Enumeration Feasible Vulnerability

MODERATE
Advisory Identifier: GHSA-4g8m-5mj5-c8xg
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CVSS 5.3
CWE-204
Published
Advisory Summary

CVE-2025-46736 is a MODERATE (CVSS 5.3) umbraco makes user enumeration feasible vulnerability (CWE-204: Observable Response Discrepancy) affecting Umbraco.Cms libraries in the NuGet ecosystem. The issue involves umbraco makes user enumeration feasible based on timing of login response. Remediation is available by upgrading affected packages to version 13.8.1, 10.8.10.

CVE-2025-46736 at a Glance

CVE Identifier CVE-2025-46736
GHSA Identifier GHSA-4g8m-5mj5-c8xg
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-204: Observable Response Discrepancy
Affected Product Umbraco.Cms
Package Ecosystem NuGet
Published Date
Last Updated

Security Impact

CVSS: 5.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2025-46736

To remediate this vulnerability, upgrade all affected Umbraco.Cms dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Umbraco.Cms fixed: 13.8.1 
Upgrade Umbraco.Cms to 13.8.1
Umbraco.Cms fixed: 10.8.10 
Upgrade Umbraco.Cms to 10.8.10
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for Umbraco.Cms

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-46736, inspect your project dependencies for Umbraco.Cms:

inspect dependencies for Umbraco.Cms

Analyze the terminal output to locate any version of Umbraco.Cms in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 13.8.1), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-204: Observable Response Discrepancy, where the product provides different responses to incoming requests in a way that reveals internal state information to an unauthorized actor outside of the intended control sphere. In Umbraco.Cms, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact Based on an analysis of the timing of post login API responses, it's possible to determine whether an account exists. ### Patches Patched in 10.8.10 and 13.8.1. ### Workarounds None available.

CVE-2025-46736 Affected Umbraco.Cms Versions

2 component(s)
Fixed Versions:
13.8.110.8.10
Product / Package Ecosystem Affected Versions Fixed Version
Umbraco.Cms
nuget/Umbraco.Cms
NuGet
≥ 11.0.0-rc1
< 13.8.1
13.8.1
Umbraco.Cms
nuget/Umbraco.Cms
NuGet
< 10.8.10
10.8.10

References

GitHub Advisory / Wiki ADVISORY
https://github.com/umbraco/Umbraco-CMS/security/advisories/GHSA-4g8m-5mj5-c8xg
NVD — CVE-2025-46736 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-46736
Security Fix Commit FIX COMMIT
https://github.com/umbraco/Umbraco-CMS/commit/14fbd20665b453cbf094ccf4575b79a9fba07e03
Security Fix Commit FIX COMMIT
https://github.com/umbraco/Umbraco-CMS/commit/34709be6cce9752dfa767dffbf551305f48839bc
Umbraco.Cms Source Repository REPOSITORY
https://github.com/umbraco/Umbraco-CMS

Frequently Asked Questions

What is CVE-2025-46736?
CVE-2025-46736 is a security vulnerability in Umbraco.Cms involving Umbraco Makes User Enumeration Feasible Based on Timing of Login Response under CWE-204: Observable Response Discrepancy.
Which Umbraco.Cms versions are affected?
Affected versions include releases prior to 13.8.1, 10.8.10 across affected packages: Umbraco.Cms.
What version fixes CVE-2025-46736?
Upgrading to 13.8.1, 10.8.10 (or the latest patched release for your respective branch) resolves the vulnerability.
Is Umbraco.Cms affected?
Yes, Umbraco.Cms is affected in releases prior to 13.8.1, 10.8.10. Upgrade your dependency to 13.8.1, 10.8.10 or later.
What is the CVSS score of CVE-2025-46736?
CVE-2025-46736 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2025-46736?
CVE-2025-46736 is classified under CWE-204: Observable Response Discrepancy (The product provides different responses to incoming requests in a way that reveals internal state information to an unauthorized actor outside of the intended control sphere.).
How can I check NuGet dependencies for CVE-2025-46736?
Run the dependency tree command: 'inspect dependencies for Umbraco.Cms'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-4g8m-5mj5-c8xg",
  "modified" : "2025-05-06T19:57:06Z",
  "published" : "2025-05-06T16:38:55Z",
  "aliases" : [ "CVE-2025-46736" ],
  "summary" : "Umbraco Makes User Enumeration Feasible Based on Timing of Login Response",
  "details" : "### Impact\nBased on an analysis of the timing of post login API responses, it's possible to determine whether an account exists.\n\n### Patches\nPatched in 10.8.10 and 13.8.1.\n\n### Workarounds\nNone available.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Umbraco.Cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.0.0-rc1"
      }, {
        "fixed" : "13.8.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Umbraco.Cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "10.8.10"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/umbraco/Umbraco-CMS/security/advisories/GHSA-4g8m-5mj5-c8xg"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-46736"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/umbraco/Umbraco-CMS/commit/14fbd20665b453cbf094ccf4575b79a9fba07e03"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/umbraco/Umbraco-CMS/commit/34709be6cce9752dfa767dffbf551305f48839bc"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/umbraco/Umbraco-CMS"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-204" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-05-06T16:38:55Z",
    "nvd_published_at" : "2025-05-06T17:16:12Z"
  }
}