| Component | n8n |
| Severity | medium (CVSS 6.1) |
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| Published (NVD) | 2026-05-04 |
| Last modified | 2026-06-17 |
| Affected versions | n8n < 1.123.32 n8n >= 2.17.0, < 2.17.4 n8n = 2.18.0 |
| Fixed in | 1.123.32, 2.17.4 |
| Weakness | CWE-601 |
| CISA KEV | not listed |
NVD description
n8n is an open source workflow automation platform. Prior to versions 1.123.32, 2.17.4, and 2.18.1, the /mcp-oauth/register endpoint accepted OAuth client registrations without authentication, allowing arbitrary redirect_uri values to be registered. When a user denies the MCP OAuth consent dialog, the handleDeny handler redirects the user to the registered redirect_uri without validation, enabling an open redirect to an attacker-controlled URL. An attacker can craft a phishing link and send it to a victim; if the victim clicks "Deny" on the consent page, they are silently redirected to an external site. This issue has been patched in versions 1.123.32, 2.17.4, and 2.18.1.
What to do
- Upgrade n8n to
1.123.32or later (or the patched release of your branch: 2.17.4). - Do not expose the component's API or UI to the internet without authentication in front of it.
Sources
Read more
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