GHSA-f6x8-65q6-j9m9: n8n has Open Redirect in MCP OAuth Consent Flow
Summary
n8n has a vulnerability where its OAuth consent flow allows attackers to register fake redirect URLs (destinations where users are sent after denying permission) without authentication. An attacker can trick a user into clicking a malicious link, and when the user clicks "Deny" on the consent dialog, they get redirected to the attacker's website instead of staying safe. This could be used for phishing (tricking users into giving up sensitive information).
Solution / Mitigation
The issue has been fixed in n8n versions 1.123.32, 2.17.4, and 2.18.1. Users should upgrade to one of these versions or later. If upgrading is not immediately possible, administrators can restrict network access to the n8n instance to prevent untrusted users from reaching the MCP OAuth endpoints, or limit access to the n8n instance to fully trusted users only. However, the source notes these workarounds do not fully remediate the risk and should only be used as short-term measures.
Vulnerability Details
EPSS: 0.0%
Yes
April 29, 2026
Classification
Affected Vendors
Affected Packages
Related Issues
Original source: https://github.com/advisories/GHSA-f6x8-65q6-j9m9
First tracked: April 29, 2026 at 08:00 PM
Classified by LLM (prompt v3) · confidence: 85%