CVE-2026-33665: n8n: LDAP Email-Based Account Linking Allows Privilege Escalation and Account Takeover
Impact 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).
Patches The issue has been fixed in n8n versions 2.4.0 and 1.121.0. Users should upgrade to one of these versions or later to remediate the vulnerability.
Workarounds If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Disable LDAP authentication until the instance can be upgraded. - Restrict LDAP directory permissions so that users cannot modify their own email attributes. - Audit existing LDAP-linked accounts for unexpected account associations.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Other sources
n8n is an open source workflow automation platform. Prior to versions 2.4.0 and 1.121.0, 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). The issue has been fixed in n8n versions 2.4.0 and 1.121.0. Users should upgrade to one of these versions or later to remediate the vulnerability. If upgrading is not immediately possible, administrators should consider the following temporary mitigations: Disable LDAP authentication until the instance can be upgraded, restrict LDAP directory permissions so that users cannot modify their own email attributes, and/or audit existing LDAP-linked accounts for unexpected account associations. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
— MITRE
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-33665?
CVE-2026-33665 has been rated as a high severity vulnerability due to its potential for privilege escalation and account takeover.
How do I fix CVE-2026-33665?
To fix CVE-2026-33665, upgrade to n8n versions 2.4.0 or 1.121.0 or later to prevent LDAP email-based account linking issues.
What are the potential impacts of CVE-2026-33665?
The potential impacts of CVE-2026-33665 include unauthorized access to accounts and escalation of privileges for an attacker.
Which versions of n8n are affected by CVE-2026-33665?
CVE-2026-33665 affects n8n versions prior to 2.4.0 and 1.121.0.
What is LDAP email-based account linking in relation to CVE-2026-33665?
LDAP email-based account linking in the context of CVE-2026-33665 refers to how n8n incorrectly associates an LDAP identity with existing local accounts, leading to possible account takeovers.