CVE-2026-33665: n8n LDAP Email-Based Account Linking Allows Vulnerability

HIGH
Advisory Identifier: GHSA-c545-x2rh-82fc
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CVSS 8.2
CWE-287
Published
Advisory Summary

CVE-2026-33665 is a HIGH (CVSS 8.2) ldap email-based account linking allows vulnerability (CWE-287: Improper Authentication) affecting n8n libraries in the npm ecosystem. The issue involves ldap email-based account linking allows privilege escalation and account takeover. Remediation is available by upgrading affected packages to version 2.4.0, 1.121.0.

CVE-2026-33665 at a Glance

CVE Identifier CVE-2026-33665
GHSA Identifier GHSA-c545-x2rh-82fc
Severity HIGH
CVSS v3.1 Base Score 8.2
CWE Classification CWE-287: Improper Authentication
Affected Product n8n
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 8.2

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2026-33665

To remediate this vulnerability, upgrade all affected n8n dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

n8n fixed: 2.4.0 
npm install n8n@2.4.0
n8n fixed: 1.121.0 
npm install n8n@1.121.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls n8n

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-33665, inspect your project dependencies using npm:

npm ls n8n

Analyze the terminal output to locate any version of n8n in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.4.0), your application is affected.

Note: The npm ls n8n command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-287: Improper Authentication, where when an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. In n8n, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## 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.

CVE-2026-33665 Affected n8n Versions

2 component(s)
Fixed Versions:
2.4.01.121.0
Product / Package Ecosystem Affected Versions Fixed Version
n8n
npm/n8n
npm
≥ 2.0.0-rc.0
< 2.4.0
2.4.0
n8n
npm/n8n
npm
< 1.121.0
1.121.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/n8n-io/n8n/security/advisories/GHSA-c545-x2rh-82fc
NVD — CVE-2026-33665 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-33665
n8n Source Repository REPOSITORY
https://github.com/n8n-io/n8n

Frequently Asked Questions

What is CVE-2026-33665?
CVE-2026-33665 is a security vulnerability in n8n involving LDAP Email-Based Account Linking Allows Privilege Escalation and Account Takeover under CWE-287: Improper Authentication.
Which n8n versions are affected?
Affected versions include releases prior to 2.4.0, 1.121.0 across affected packages: n8n.
What version fixes CVE-2026-33665?
Upgrading to 2.4.0, 1.121.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is n8n affected?
Yes, n8n is affected in releases prior to 2.4.0, 1.121.0. Upgrade your dependency to 2.4.0, 1.121.0 or later.
What is the CVSS score of CVE-2026-33665?
CVE-2026-33665 has a CVSS v3.1 base score of 8.2 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N.
What CWE is associated with CVE-2026-33665?
CVE-2026-33665 is classified under CWE-287: Improper Authentication (When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.).
How can I check npm dependencies for CVE-2026-33665?
Run the dependency tree command: 'npm ls n8n'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-c545-x2rh-82fc",
  "modified" : "2026-03-25T21:09:13Z",
  "published" : "2026-03-25T21:09:13Z",
  "aliases" : [ "CVE-2026-33665" ],
  "summary" : "n8n: LDAP Email-Based Account Linking Allows Privilege Escalation and Account Takeover",
  "details" : "## Impact\nWhen 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.\n\n- LDAP authentication must be configured and active (non-default).\n\n## Patches\nThe 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.\n\n## Workarounds\nIf upgrading is not immediately possible, administrators should consider the following temporary mitigations:\n- Disable LDAP authentication until the instance can be upgraded.\n- Restrict LDAP directory permissions so that users cannot modify their own email attributes.\n- Audit existing LDAP-linked accounts for unexpected account associations.\n\nThese workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "n8n"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.0.0-rc.0"
      }, {
        "fixed" : "2.4.0"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "n8n"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.121.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/n8n-io/n8n/security/advisories/GHSA-c545-x2rh-82fc"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-33665"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/n8n-io/n8n"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-287" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-25T21:09:13Z",
    "nvd_published_at" : "2026-03-25T18:16:32Z"
  }
}