CVE-2026-33665
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedn8n 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceIn n8n versions prior to 2.4.0 and 1.121.0, when LDAP authentication is enabled, the system automatically links an LDAP identity to a local account if the LDAP email attribute matches the local account's email. An authenticated LDAP user can exploit this by setting their LDAP email to match another user's email (including an administrator), granting them full access to that account. This account linkage persists permanently even if the LDAP email is subsequently reverted, enabling permanent account takeover.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 1.121.0>= 2.0.0, < 2.4.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- High
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check n8n versionAccess the n8n instance and navigate to Settings > About, or query the API endpoint /rest/settings, to find the installed version numberAffected if Version is less than 1.121.0, or version is 2.0.0 or higher but less than 2.4.0
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Verify LDAP authentication is enabledNavigate to Settings > LDAP in the n8n admin panel, or inspect the environment variables for LDAP_ENABLED=true or LDAP configuration in the databaseAffected if LDAP authentication is currently enabled in the n8n instance
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List all users with LDAP identity linkageQuery the database or use the n8n API to retrieve all users and inspect the identity provider field; look for users where providerType is 'ldap' and linkedTo contains a local account referenceAffected if Multiple users exist with LDAP identities linked to local accounts, especially admin-level accounts
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Audit for unexpected admin account accessReview n8n audit logs or authentication logs for LDAP users accessing accounts other than their own, particularly admin account logins from LDAP identities that do not match the expected userAffected if Audit logs show LDAP users accessing or logging into admin or other privileged local accounts they should not own
A user is affected if n8n is running a vulnerable version with LDAP enabled and there are LDAP-linked accounts, particularly if admin accounts are linked to LDAP identities or show suspicious access patterns.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped1.121.02.4.0
Upgrade to n8n versions 2.4.0 or 1.121.0 or later. If immediate upgrade is not feasible, disable LDAP authentication, restrict LDAP directory permissions to prevent users from modifying their email attributes, and audit existing LDAP-linked accounts for unauthorized associations.
1.121.0 (for 1.x branch) or 2.4.0 (for 2.x branch)
- 1. Schedule a maintenance window for the upgrade process
- 2. Create a complete backup of the n8n database and configuration files
- 3. Determine which version branch you're currently on (0.x/1.x or 2.x)
- 4. If on 1.x version line: Upgrade n8n to version 1.121.0 or later
- 5. If on 2.x version line: Upgrade n8n to version 2.4.0 or later
- 6. After upgrade, audit all LDAP-linked accounts in n8n for unexpected account associations using the admin panel
- 7. Verify that LDAP authentication now properly validates email attribute matching before account linking
- 8. Test login with an LDAP user to confirm the fix works correctly
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation1.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-33665 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-33665 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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