CVE-2026-31832: Umbraco CMS

Medium severity, CVSS 5.4. EPSS: 0.3% chance of exploitation in the next 30 days.

Umbraco is an ASP.NET CMS. From 14.0.0 to before 16.5.1 and 17.2.2, A broken object-level authorization vulnerability exists in a backoffice API endpoint that allows authenticated users to assign domain-related data to content nodes without proper authorization checks. The issue is caused by insufficient authorization enforcement on the affected API endpoint, whereby via an API call, domains can be set on content nodes that the editor does not have permission to access (either via user group privileges or start nodes). This vulnerability is fixed in 16.5.1 and 17.2.2.

Affected products

• Umbraco Umbraco CMS: from 14.0.0, before 16.5.1 (fixed in 16.5.1); from 17.0.0, before 17.2.2 (fixed in 17.2.2)

Published 2026-03-10. Last modified 2026-06-17.