A flaw was found in the backchannel logout endpoint of the keycloak-services component, which is part of the Red Hat Build of Keycloak. This component handles authentication and session management for applications. The issue occurs when an OIDC identity provider is configured to skip signature validation. In this specific setup, the system incorrectly accepts logout requests that have no cryptographic signature. An attacker who knows certain technical details about a user's session can use this flaw to force that user to be logged out, potentially disrupting their work.
A flaw was found in the hostname matching logic within the ClientUpdaterSourceHostsCondition of Keycloak. When a wildcard domain (e.g., .example.com) is configured as a trusted source host in a client policy, the matching mechanism performs a simple suffix check without ensuring a proper subdomain boundary (a preceding dot). An unauthenticated attacker whose connecting IP address reverse-resolves to a crafted hostname ending in the trusted suffix (e.g., attackerexample.com) can satisfy the condition. This allows the attacker to bypass source-host restrictions intended to limit client registration or update operations to trusted domains. Successful exploitation causes policy executors to run as if the request originated from a legitimate trusted source, which can weaken or bypass security constraints applied to client management.
A flaw was found in Keycloak. An authorization bypass vulnerability in the Keycloak Admin API allows any authenticated user, even those without administrative privileges, to enumerate the organization memberships of other users. This information disclosure occurs if the attacker knows the victim's unique identifier (UUID) and the Organizations feature is enabled.
A flaw was found in Keycloak’s WebAuthn registration component. This vulnerability allows an attacker to bypass the configured attestation policy and register untrusted or forged authenticators via submission of an attestation object with fmt: "none", even when the realm is configured to require direct attestation. This can lead to weakened authentication integrity and unauthorized authenticator registration.
A flaw was found in Keycloak. An authenticated attacker can perform Server-Side Request Forgery (SSRF) by manipulating the clientsessionhost parameter during refresh token requests. This occurs when a Keycloak client is configured to use the backchannel.logout.url with the application.session.host placeholder. Successful exploitation allows the attacker to make HTTP requests from the Keycloak server’s network context, potentially probing internal networks or internal APIs, leading to information disclosure.
A flaw was found in Keycloak. An authenticated user with the view-users role could exploit a vulnerability in the UserResource component. By accessing a specific administrative endpoint, this user could improperly retrieve user attributes that were configured to be hidden. This unauthorized information disclosure could expose sensitive user data.
A flaw was found in Keycloak. A remote attacker can exploit differential error messages during the identity-first login flow when Organizations are enabled. This vulnerability allows an attacker to determine the existence of users, leading to information disclosure through user enumeration.