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Servers and applications

CVE-2026-126386

n8n before 1.123.89 Open Redirect via MCP OAuth Dynamic Client Registration

Severity
Medium 5.1
Published
13 Nov 2026
Last changed
13 Nov 2026
Added to UpHeron
13 Nov 2026
Fixed in
1.123.89, 2.45.5, 2.46.1, 3.0.1
Weakness
Open redirect (CWE-601)
Attack
Over the network · No login needed · Needs someone to click or open something
CVSS vector
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
Sources
CVE Program

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.

From the CVE Program.

Affected software

SoftwareAffected versions
n8nServers and applications · cna:n8n-io|n8n
  • Every version before 1.123.89
  • From 2.0.0 before 2.45.5
  • From 2.46.0 before 2.46.1
  • From 3.0.0 before 3.0.1

References

  • CVE.org https://www.cve.org/CVERecord?id=CVE-2026-126386