{"id":"CVE-2026-18206","title":"A flaw was found in the keycloak-services component of Keycloak, which provides identity and access management services","summary":"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 …","severity":"low","cvss":3.7,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","cwe":["CWE-20"],"vendor":"redhat","product":"build_of_keycloak","affected":["build_of_keycloak"],"published":"2026-07-31","updated":"2026-08-07","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-18206","references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-18206","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2508292","label":"secalert@redhat.com"}],"tags":["nvd"],"epss":0.00201,"epssPercentile":0.10259,"ingestedAt":"2026-08-08T14:22:57.344Z","slug":"CVE-2026-18206","body":"## Overview\n\nA 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.\n\n## Affected\n\n- `build_of_keycloak`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":20,"depthScoreParts":{"impact":20.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}