CVE-2026-31834
Umbraco Affected by Vertical Privilege Escalation via Missing Authorization Checks
Description
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.
CVSS Vector Breakdown
AV:NAttack VectorAC:LAttack ComplexityPR:HPrivileges RequiredUI:NUser InteractionS:UScopeC:HConfidentialityI:HIntegrityA:HAvailabilityWeaknesses
Affected Products
Attack Graph
Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.
Exploitability
MITRE ATT&CK
3 techniquesReferences
Timeline
Unlock Complete Vulnerability Intelligence
Get the full picture for CVE-2026-31834 and every CVE in our database. Create a free account — no credit card required.
Create Free Account