CVE-2026-27449

Description

A vulnerability has been identified in Umbraco Engage 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.

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading?

References

Are there any links users can visit to find out more?

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.

A critical operation is accessible without requiring any authentication. Typical impact: any user can invoke the privileged function.

CVE-2026-27449 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (17.1.1, 16.2.1); upgrading removes the vulnerable code path.

Kodem intelligence

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

1. What is CVE-2026-27449? CVE-2026-27449 is a high-severity missing authentication for critical function vulnerability in Umbraco.Engage.Forms (nuget), affecting versions >= 17.0.0, < 17.1.1. It is fixed in 17.1.1, 16.2.1. A critical operation is accessible without requiring any authentication.
2. How severe is CVE-2026-27449? CVE-2026-27449 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of Umbraco.Engage.Forms are affected by CVE-2026-27449? Umbraco.Engage.Forms (nuget) versions >= 17.0.0, < 17.1.1 is affected.
4. Is there a fix for CVE-2026-27449? Yes. CVE-2026-27449 is fixed in 17.1.1, 16.2.1. Upgrade to this version or later.
5. Is CVE-2026-27449 exploitable, and should I be worried? Whether CVE-2026-27449 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-27449 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-27449?
   • Upgrade Umbraco.Engage.Forms to 17.1.1 or later
   • Upgrade Umbraco.Engage.Forms to 16.2.1 or later