CVE-2026-33665: n8n: LDAP Email-Based Account Linking Allows Privilege Escalation and Account Takeover

When LDAP authentication is enabled, n8n automatically linked an LDAP identity to an existing local account if the LDAP email attribute matched the local account’s email. An authenticated LDAP user who could control their own LDAP email attribute could set it to match another user’s email — including an administrator’s — and upon login gain full access to that account. The account linkage persisted even if the LDAP email was later reverted, resulting in a permanent account takeover.

• LDAP authentication must be configured and active (non-default).