n8n's Credential Authorization Bypass in dynamic-node-parameters Allows Foreign API Key Replay
High8.5CVE-2026-42226 · Published Apr 29, 2026 · updated May 8, 2026
## Impact 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. ## Patches The issue has been fixed in n8n version 2.18.0. Users should upgrade to this version or later to remediate the vulnerability. ## Workarounds If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Restrict n8n access to fully trusted users only. - Avoid sharing workflows with users who should not have access to the credentials those workflows reference. These workarounds do not fully remediate...
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| n8n npm | >= 2.17.0, < 2.17.5 | 2.17.5 |
| < 1.123.33 | 1.123.33 |
Details and references
## Impact 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. ## Patches The issue has been fixed in n8n version 2.18.0. Users should upgrade to this version or later to remediate the vulnerability. ## Workarounds If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Restrict n8n access to fully trusted users only. - Avoid sharing workflows with users who should not have access to the credentials those workflows reference. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:L
- Severity from
- GitHub (reviewed advisory)
- Weakness
- CWE-862
- Also known as
- CVE-2026-42226
More n8n advisories
All n8n| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Apr 29 | n8n has XML Node Prototype Pollution that to RCE Critical9.9Apr 29 | Critical9.9 | 1.123.32+2 more |
| Apr 29 | n8n has Prototype Pollution in XML Webhook Body Parser that Leads to RCECritical10.0Apr 29 | Critical10.0 | 1.123.32+2 more |
| Apr 29 | n8n Vulnerable to XSS via MCP OAuth clientHigh8.2Apr 29 | High8.2 | 1.123.32+2 more |
| Apr 29 | n8n has a Python Task Runner Sandbox Escape VulnerabilityHigh7.5Apr 29 | High7.5 | 1.123.32+2 more |
| Apr 29 | n8n has Public API Variables IDOR that Allows Cross-Project Secret DisclosureMedium7.7Apr 29 | Medium7.7 | 1.123.32+2 more |
| Apr 29 | n8n Vulnerable to Unauthenticated Denial of Service via MCP Client RegistrationHigh7.5Apr 29 | High7.5 | 1.123.32+2 more |