CVE-2026-18571 Keycloak-services: keycloak-services: fgap v2 group assignment bypass during user creation
Sub-administrators can bypass group restrictions during user creation, granting unauthorized group memberships and potential privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-18571?
CVE-2026-18571 is a medium-severity missing authorization vulnerability in Redhat Build of Keycloak, published on 2 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
A flaw was found in the user creation component of Keycloak when Fine-Grained Admin Permissions V2 (FGAP V2) is enabled. This issue allows a sub-administrator with permission to create users to add those users to any group, even groups the sub-administrator is not authorized to manage. This could lead to unauthorized access to sensitive information or elevated privileges for the newly created users.
Weakness: CWE-862
Which versions are affected by CVE-2026-18571?
1 open source package ship an affected version, including keycloak. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
keycloak Bitnami | All versions | 26.7.3 |
Products include Redhat Build of Keycloak.
How do I fix CVE-2026-18571?
Upgrade keycloak to 26.7.3 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-18571 being exploited?
There is no known exploitation of CVE-2026-18571 in the wild and no public exploit code.
Other vulnerabilities in Redhat Build of Keycloak
- CVE-2026-15572 Keycloak-services: keycloak-services: dcr protocol mapper type-swap policy bypass allows privilege escalation
- CVE-2026-3047 Keycloak SAML Broken has Authentication Bypass by Primary Weakness
- CVE-2026-15573 Keycloak-services: keycloak-services: authorization bypass via unnormalized uri matching in pathmatcher
- CVE-2026-16102 Keycloak-services: keycloak-services: default dcr policy allows role forgery via user property mappers
- CVE-2026-1609 Org.keycloak/keycloak-quarkus-server: keycloak: unauthorized access via jwt authorization grant with disabled users
Sources
Also known as BIT-keycloak-2026-18571, CLEANSTART-2026-MZ50851, GHSA-5vmc-qhfj-qxc3.