A flaw was found in Keycloak. An authenticated user with the uma_protection role can bypass User-Managed Access (UMA) policy validation. This allows the attacker to include resource identifiers owned by other users in a policy creation request, even if the URL path specifies an attacker-owned resource.
Consequently, the attacker gains unauthorized permissions to victim-owned resources, enabling them to obtain a Requesting Party Token (RPT) and access sensitive information or perform unauthorized actions.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
None
No disruption
CVSS Vector v3.1
Weakness Type (CWE)
Vulnerable Products 5
| Configuration | From (including) | Up to (excluding) |
|---|---|---|
|
Redhat Build_Of_Keycloak
cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:text-only:*:*:*
|
— | — |
|
Redhat Build_Of_Keycloak
cpe:2.3:a:redhat:build_of_keycloak:26.2:*:*:*:text-only:*:*:*
|
— | — |
|
Redhat Build_Of_Keycloak
cpe:2.3:a:redhat:build_of_keycloak:26.2.15:*:*:*:text-only:*:*:*
|
— | — |
|
Redhat Build_Of_Keycloak
cpe:2.3:a:redhat:build_of_keycloak:26.4:*:*:*:text-only:*:*:*
|
— | — |
|
Redhat Build_Of_Keycloak
cpe:2.3:a:redhat:build_of_keycloak:26.4.11:*:*:*:text-only:*:*:*
|
— | — |
References 6
https://access.redhat.com/errata/RHSA-2026:6475
secalert@redhat.com
https://access.redhat.com/errata/RHSA-2026:6476
secalert@redhat.com
https://access.redhat.com/errata/RHSA-2026:6477
secalert@redhat.com
https://access.redhat.com/errata/RHSA-2026:6478
secalert@redhat.com
https://access.redhat.com/security/cve/CVE-2026-4636
secalert@redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2450251
secalert@redhat.com