Description
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.
Affected products
redhat: build of keycloak
References4
- access.redhat.com/security/cve/CVE-2026-18206 Vendor Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2508292 Issue TrackingVendor Advisory
- access.redhat.com/errata/RHSA-2026:95761
- access.redhat.com/errata/RHSA-2026:95762
Metrics
- CVSS 3.1
-
3.7
LOW
Score source: NVD
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N - EPSS — exploit probability
- 0% percentile: 31 · as of 13 November 2026
- CWE
- CWE-20
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