Keycloak Token Exchange Bypass Ignoring Org Restriction
CVE-2026-18215 Published on July 31, 2026
Keycloak-services: keycloak-services: microsoft external access-token exchange bypasses configured tenant
Keycloak provides a way to let users log in using Microsoft accounts while restricting access to a specific organization (tenant). A flaw was discovered where this restriction is ignored when using the token exchange feature. This means an attacker with a valid Microsoft token from a completely different organization could gain access to the Keycloak realm, potentially accessing sensitive data or performing unauthorized actions.
Vulnerability Analysis
CVE-2026-18215 can be exploited with network access, and requires small amount of user privileges. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.
Timeline
Reported to Red Hat.
Made public.
Weakness Type
What is an authentification Vulnerability?
When an actor claims to have a given identity, the software does not prove or insufficiently proves that the claim is correct.
CVE-2026-18215 has been classified to as an authentification vulnerability or weakness.
Products Associated with CVE-2026-18215
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