CVE-2026-31834 — Umbraco Affected by Vertical Privilege Escalation via Missing Authorization Checks
Umbraco is an ASP.NET CMS. From 15.3.1 to before 16.5.1 and 17.2.2, A privilege escalation vulnerability has been identified in Umbraco CMS. Under certain conditions, authentica…
Published: 2026-03-10 · CVSS: 7.2 · CVSS 3.1
Umbraco is an ASP.NET CMS. From 15.3.1 to before 16.5.1 and 17.2.2, A privilege escalation vulnerability has been identified in Umbraco CMS. Under certain conditions, authenticated backoffice users with permission to manage users, may be able to elevate their privileges due to insufficient authorization enforcement when modifying user group memberships. The affected functionality does not properly validate whether a user has sufficient privileges to assign highly privileged roles. This vulnerability is fixed in 16.5.1 and 17.2.2.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7