CVE-2026-18207 Keycloak-services: keycloak-services: client policy source-group condition bypass via duplicate group name matching
Attackers with client management privileges can bypass security policies by exploiting duplicate group names, allowing unauthorized client registration or updates.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-18207?
CVE-2026-18207 is a medium-severity authentication bypass vulnerability in Redhat Build of Keycloak, published on 29 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A flaw was found in the client policy enforcement mechanism of Keycloak. The issue occurs when the system checks group membership by name instead of a unique identifier. An attacker with client management privileges could bypass security policies by joining a group with a matching name in a different part of the group hierarchy, potentially allowing them to register or update clients without following required security hardening profiles.
Weakness: CWE-285
Which versions are affected by CVE-2026-18207?
It affects 1 product.
Products include Redhat Build of Keycloak.
How do I fix CVE-2026-18207?
No fix has been published for CVE-2026-18207 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-18207 being exploited?
There is no known exploitation of CVE-2026-18207 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 GHSA-rfxv-6gx8-3fm6.