Vulnerability · Published May 4, 2026 · Assigned by GitHub_M

CVE-2026-42230n8n: Open Redirect in MCP OAuth Consent Flow

Medium 5.1

In plain English

A medium-severity open redirect in n8n from n8n-io. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)5.1Medium

Exploit odds (30 days)0.2%top 92.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	n8n	1.123.32	GHSA-f6x8-65q6-j9m9
npm	n8n	2.18.1	GHSA-f6x8-65q6-j9m9
npm	n8n	2.17.4	GHSA-f6x8-65q6-j9m9

Affected products (as reported)

Vendor	Product	Versions
n8n-io	n8n	< 1.123.32>= 2.17.0, < 2.17.4>= 2.18.0, < 2.18.1

Weakness: CWE-601 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N

References

https://github.com/n8n-io/n8n/security/advisories/GHSA-f6x8-65q6-j9m9 x_refsource_CONFIRM