CVE-2026-42226 in n8n
Summary
by MITRE • 05/04/2026
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.
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Analysis
by VulDB Data Team • 05/22/2026
The vulnerability in n8n workflow automation platform represents a critical authorization bypass flaw that undermines the security boundaries between users and their credentials. This issue affects versions prior to 1.123.33 and 2.17.5, where the dynamic-node-parameters endpoints failed to validate credential ownership during authentication processes. The flaw specifically targets the credential verification mechanism that should ensure users can only access credentials they legitimately possess, creating a pathway for unauthorized credential usage across user boundaries.
The technical implementation of this vulnerability stems from insufficient access control checks within the credential resolution process. When an authenticated user accesses a shared workflow, the system should validate that any credential references provided in the request belong to the requesting user. However, the system failed to enforce this validation, allowing attackers to submit credential IDs from other users within the request body. This oversight creates a scenario where the backend system decrypts and utilizes foreign credentials during helper execution paths, particularly when the attacker also controls the destination URL parameter.
The operational impact of this vulnerability extends beyond simple credential theft, as it enables attackers to perform authenticated requests against attacker-controlled infrastructure using legitimate user credentials. The exploitation process allows unauthorized users to force the backend system to establish connections to malicious endpoints, effectively enabling credential exfiltration and potential account takeover scenarios. This issue affects all node types that utilize dynamic credential resolution, making it particularly dangerous as it can compromise any workflow component that relies on external authentication mechanisms.
The vulnerability aligns with CWE-285 (Improper Authorization) and represents a classic case of insufficient access control validation within workflow automation systems. From an adversarial perspective, this flaw maps to ATT&CK technique T1566 (Phishing for Information) and T1078 (Valid Accounts) as attackers can leverage stolen credentials to access additional systems and data. The issue demonstrates how shared workflow environments can create unexpected attack vectors when proper authorization boundaries are not maintained between users with different privilege levels.
Organizations using n8n should immediately upgrade to versions 1.123.33, 2.17.5, or 2.18.0 to remediate this vulnerability. The patch addresses the core authorization bypass by implementing proper credential ownership validation during dynamic parameter resolution. Additional mitigations include monitoring for unusual credential usage patterns, implementing stricter access controls for shared workflows, and conducting regular security audits of credential handling mechanisms within automated workflow systems. The fix ensures that all credential references are validated against the requesting user's authorization context before any decryption or usage occurs, preventing the exploitation scenario described in the vulnerability report.