CVE-2026-18203 — Keycloak-services: keycloak-services: group policy extendchildren matches sibling group path prefixes
A flaw was found in the group policy evaluation logic of Keycloak, an identity and access management solution. When a group policy is set to extend permissions to child groups, …
Published: 2026-07-31 · CVSS: 6.5 · CVSS 3.1
A flaw was found in the group policy evaluation logic of Keycloak, an identity and access management solution. When a group policy is set to extend permissions to child groups, the system incorrectly uses a simple text-based prefix check to verify group membership. This allows a user who belongs to a different group with a similar starting name to bypass security checks and gain unauthorized access to administrative functions or protected resources.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7