n8n Token Exchange Flaw Could Let Attackers Log In as Users From Another Issuer

n8n, the workflow automation platform, handed out the wrong accounts at login. On Enterprise instances configured to trust more than one external token issuer, it matched an incoming JWT to a local user on the sub claim alone and ignored iss.

A valid token from issuer A carrying a sub that belongs to someone under issuer B logged you in as them. Their password never