Red Hat Keycloak keycloak-services improper authorization

Summaryinfo

A vulnerability classified as problematic was found in Red Hat Keycloak. This impacts an unknown function of the component keycloak-services. Executing a manipulation can lead to improper authorization. This vulnerability is tracked as CVE-2026-18206. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability has been found in Red Hat Keycloak (version unknown) and classified as problematic. This vulnerability affects an unknown function of the component keycloak-services. The manipulation with an unknown input leads to a improper authorization vulnerability. The CWE definition for the vulnerability is CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at access.redhat.com. This vulnerability was named CVE-2026-18206 since 07/29/2026. The exploitation appears to be easy. The attack can be initiated remotely. Additional levels of successful authentication are required for exploitation. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 07/31/2026). This vulnerability is assigned to T1548.002 by the MITRE ATT&CK project.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

• Red Hat

Name

• Keycloak

License

• open-source

Website

• Vendor: https://www.redhat.com/

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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