CVE-2026-31834
Umbraco Affected by Vertical Privilege Escalation via Missing Authorization Checks
CVSS Score
7.2
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-269 CWE-284 CWE-862 |
| Vendor | umbraco |
| Product | umbraco-cms |
| Published | Mar 10, 2026 |
| Last Updated | Mar 11, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
umbraco / Umbraco-CMS
>= 15.3.1, < 16.5.1 >= 17.0.0, < 17.2.1