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Medium · 6.8 CVE-2026-18215 EUVD-2026-51480GHSA-v8h5-7wp9-qxxv

Keycloak-services: keycloak-services: microsoft external access-token exchange bypasses configured tenant

Published Jul 31, 2026 · Updated Sep 16, 2026 · Assigned by redhat

Description

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.

Affected products

VendorProductAffectedFixed
Red Hat Red Hat build of Keycloak 26.6 — —
Red Hat Red Hat build of Keycloak 26.6.7 — —
Red Hat Red Hat Data Grid 8 — —
Red Hat Red Hat JBoss Enterprise Application Platform Expansion Pack — —
Red Hat Red Hat Single Sign-On 7 — —

Advisories 1

References