CVE-2026-126386

Description

n8n before 1.123.89, 2.x before 2.45.5, 2.46.x before 2.46.1, and 3.x before 3.0.1 contains an open redirect vulnerability in the unauthenticated MCP OAuth dynamic client registration flow, which accepts arbitrary redirect_uri values via the /mcp-oauth/register endpoint. Attackers can send victims crafted /mcp-oauth/authorize URLs that redirect them to attacker-controlled sites before instance checks run, enabling phishing.

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

• 5.1CVSS 4.0, Mediumfrom the CNA (VulnCheck)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N
• 4.7CVSS 3.1, Mediumfrom the CNA (VulnCheck)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

No explicit remediation statement is available on this page yet. Consult the original record and vendor references before choosing a fix.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

Timeline

1. 13 Nov 2026 Published

Weakness

• CWE-601

References

• GitHub Security Advisory (GHSA-rc3w-8jc8-7x3w)vendor-advisory
• VulnCheck Advisory: n8n before 1.123.89 Open Redirect via MCP OAuth Dynamic Client Registrationthird-party-advisory