PT-2026-66723 · Red Hat · Red Hat Build Of Keycloak+3

CVE-2026-18206 · Published 2026-07-31 · Updated 2026-07-31

Mitre

CVSS v3.1

3.7

Low

Base vector

AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

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.

Fix

RCE

Weakness Enumeration

CWE-20

Related Identifiers

CVE-2026-18206

Affected Products

Red Hat Build Of Keycloak

Red Hat Data Grid 8

Red Hat Jboss Enterprise Application Platform Expansion Pack

Red Hat Single Sign-On 7

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-18206 · Security Note
• https://access.redhat.com/security/cve/CVE-2026-18206 · Note
• https://bugzilla.redhat.com/show_bug.cgi?id=2508292 · Note