CVE-2026-27449
Published: 26 February 2026
Summary
CVE-2026-27449 is a high-severity Improper Access Control (CWE-284) vulnerability. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 21.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 AC-14 (Permitted Actions Without Identification or Authentication) and AC-3 (Access Enforcement).
Deeper analysis
CVE-2026-27449 is a vulnerability in Umbraco Engage, a business intelligence platform, affecting versions prior to 16.2.1 and 17.1.1. Certain API endpoints are exposed without authentication or authorization checks, allowing direct network access without a valid session or user credentials. By supplying a user-controlled identifier parameter, such as ?id=, attackers can retrieve sensitive data associated with arbitrary records. The lack of access control enables enumeration attacks, where identifiers can be iterated to extract data at scale. The issue is rated with a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N) and is associated with CWE-284 (Improper Access Control), CWE-306 (Missing Authentication for Critical Function), and CWE-639 (Authorization Bypass Through User-Controlled Key).
An unauthenticated attacker with network access can exploit this vulnerability by directly querying the affected endpoints. They can achieve arbitrary record access using predictable or enumerable identifiers, leading to the disclosure of sensitive Engage-related data, such as analytics, tracking data, customer information, or other managed content. The confidentiality impact is high, with no identified effects on integrity or availability. Exploitation requires no privileges, user interaction, or special conditions beyond network reachability.
Patches have been released by Umbraco, and users are advised to update to version 16.2.1 or 17.1.1 to mitigate the issue. No workarounds are available. Additional details are provided in the GitHub security advisory at https://github.com/umbraco/Umbraco.Engage.Issues/security/advisories/GHSA-86vq-ccwf-rm62.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-8896
Vulnerability details
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Unauthenticated API exposure with IDOR (CWE-639/306/284) in public-facing Umbraco Engage web app directly enables T1190 exploitation for arbitrary sensitive data retrieval.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Enforces approved authorizations for logical access to information and system resources, directly addressing the lack of authentication and authorization checks on vulnerable API endpoints.
Limits actions permitted without identification or authentication, preventing unauthenticated access to sensitive data via exposed API endpoints.
Requires unique identification and authentication for non-organizational users, mitigating unauthenticated remote access to arbitrary records through the affected endpoints.