GHSA-M6QJ-3MPP-57V8 Keycloak: Insufficient verification proof scoping enables identity provider account linking attack and account compromise

A flaw was found in Keycloak. The cross-session verification proof is keyed only by local userId, idpAlias and is not bound to the upstream identity that was actually verified, so a second upstream account on the same IdP can consume it and get linked to the victim's local account...

Keycloak: Insufficient verification proof scoping enables identity provider account linking attack and account compromise

A flaw was found in Keycloak. The cross-session verification proof is keyed only by local userId, idpAlias and is not bound to the upstream identity that was actually verified, so a second upstream account on the same IdP can consume it and get linked to the victim's local account...

CVE-2026-9087

A flaw was found in Keycloak. The cross-session verification proof is keyed only by local userId, idpAlias and is not bound to the upstream identity that was actually verified, so a second upstream account on the same IdP can consume it and get linked to the victim's local account...