Improper Access ControlWeakness · CWE-284

CVE-2026-27449

HIGH · 7.5 CVSS v3.1 Published 2026-02-26
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Umbraco Engage is a business intelligence platform. A vulnerability has been identified in Umbraco Engage prior to versions 16.2.1 and 17.1.1 where certain API endpoints are exposed without enforcing authentication or authorization checks. The affected endpoints can be accessed directly over the network without requiring a valid session or user credentials. By supplying a user-controlled identifier parameter (e.g., ?id=), an attacker can retrieve sensitive data associated with arbitrary records. Because no access control validation is performed, the endpoints are vulnerable to enumeration attacks, allowing attackers to iterate over identifiers and extract data at scale. An unauthenticated attacker can retrieve sensitive Engage-related data by directly querying the affected API endpoints. The vulnerability allows arbitrary record access through predictable or enumerable identifiers. The confidentiality impact is considered high. No direct integrity or availability impact has been identified. The scope of exposed data depends on the deployment but may include analytics data, tracking data, customer-related information, or other Engage-managed content. The vulnerability affects both v16 and v17. Patches have already been released. Users are advised to update to 16.2.1 or 17.1.1. No known workarounds are available.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Umbraco Engage versions prior to 16.2.1 and 17.1.1 contain API endpoints that lack authentication and authorization enforcement. Attackers can directly access these endpoints by supplying identifier parameters (e.g., ?id=) to retrieve sensitive data. The vulnerability enables enumeration attacks where attackers iterate over predictable identifiers to extract analytics, tracking, or customer data at scale.

MitigationUpdate Umbraco Engage to version 16.2.1 or 17.1.1 to apply the patch that enforces authentication and authorization on the affected API endpoints. No workarounds are available.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Umbraco Engage installation
    Identify if Umbraco Engage (formerly MvcMate or Umbraco Analytics) is installed in your environment by checking your deployed packages, dependencies, or installed modules.
    Affected if Umbraco Engage is present in the environment
  2. Determine installed version
    Locate the installed version of Umbraco Engage in your project files, package manifest, or deployment metadata. Common locations include the package.config file, .csproj references, or the NuGet package manager.
    Affected if The installed version is prior to 16.2.1 or prior to 17.1.1 (or version cannot be determined)
  3. Identify exposed API endpoints
    Review your web application for API endpoints that belong to Umbraco Engage, particularly those accepting identifier parameters via query strings such as ?id= or similar parameter patterns.
    Affected if Umbraco Engage API endpoints accepting id parameters are publicly accessible
  4. Test endpoint authentication
    Attempt to access the identified Umbraco Engage API endpoints without providing valid authentication credentials or session tokens. Observe whether the request is allowed or rejected.
    Affected if Requests to Umbraco Engage API endpoints succeed without authentication (HTTP 200 response with data returned)
  5. Verify authorization enforcement
    If endpoints respond, test whether different identifier values (e.g., sequential or predictable IDs) return different data without requiring elevated privileges.
    Affected if Different identifier values return distinct sensitive data without authorization checks

You are affected if Umbraco Engage is installed with a version prior to 16.2.1 or 17.1.1 AND the Engage API endpoints are accessible without authentication.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update Umbraco Engage to version 16.2.1 or 17.1.1 to apply the patch that enforces authentication and authorization on the affected API endpoints. No workarounds are available.

Recommended fix High confidence

16.2.1 (for v16.x) or 17.1.1 (for v17.x)

  1. 1. Identify the current version of Umbraco Engage installed in your environment by checking the application configuration or package references.
  2. 2. Determine which version branch (v16 or v17) is currently in use.
  3. 3. For installations on v16.x branch: Upgrade Umbraco Engage to version 16.2.1 or later.
  4. 4. For installations on v17.x branch: Upgrade Umbraco Engage to version 17.1.1 or later.
  5. 5. Use your package manager (such as NuGet) to perform the upgrade: `dotnet add package Umbraco.Engage --version <fixed-version>` or update through your CMS package management interface.
  6. 6. After upgrading, verify that authentication is now enforced on the previously affected API endpoints by attempting to access them without credentials.
  7. 7. Confirm the vulnerability is remediated by ensuring the API endpoints return 401/403 errors when accessed without valid authentication.

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,390
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-27449 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data