CVE-2026-55672 ZITADEL: Missing client_id binding in OIDC authorization code exchange and refresh token flows (RFC 6749 Section 4.1.3 violation)

ZITADEL is an open source identity management platform. Prior to 3.4.12 and 4.15.2, ZITADEL's OAuth2 and OIDC CodeExchange, RefreshToken, and device token flows fail to verify that the requesting client matches the client that initiated the authorization flow, allowing intercepted grants or refre...

CVE-2026-55672

Summary (concrete details) : The CVE concerns Zitadel, an open-source identity management platform. The vulnerability occurs in the OAuth2/OIDC CodeExchange and RefreshToken flows (and related device token flow) where verification that the requesting client matches the originally authorized clien...