CVE-2026-18206 — Keycloak-services: keycloak-services: client policy source-host wildcard domain matching bypass
A flaw was found in the keycloak-services component of Keycloak, which provides identity and access management services. The issue occurs when a realm administrator uses a wildc…
Published: 2026-07-31 · CVSS: 3.7 · CVSS 3.1
A flaw was found in the keycloak-services component of Keycloak, which provides identity and access management services. The issue occurs when a realm administrator uses a wildcard domain (like *.example.com) to restrict which hosts can register or update clients. Due to improper validation, the system accepts any hostname that ends with the specified domain suffix, even if it is not a legitimate subdomain. An attacker who can control the reverse DNS of their connection can bypass these host-based restrictions, potentially allowing unauthorized client modifications.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7