GHSA-f6x8-65q6-j9m9

Suggest an improvement
Source
https://github.com/advisories/GHSA-f6x8-65q6-j9m9
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-f6x8-65q6-j9m9/GHSA-f6x8-65q6-j9m9.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-f6x8-65q6-j9m9
Aliases
Published
2026-04-29T21:10:17Z
Modified
2026-05-08T01:49:37Z
Severity
  • 4.7 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N CVSS Calculator
  • 5.1 (Medium) CVSS_V4 - 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 CVSS Calculator
Summary
n8n has Open Redirect in MCP OAuth Consent Flow
Details

Impact

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.

Patches

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 to remediate the vulnerability.

Workarounds

If upgrading is not immediately possible, administrators should consider the following temporary mitigations:

  • Restrict network access to the n8n instance to prevent untrusted users from reaching the MCP OAuth endpoints.
  • Limit access to the n8n instance to fully trusted users only.

These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

Database specific 
{
    "cwe_ids":  [
        "CWE-601"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2026-04-29T21:10:17Z",
    "nvd_published_at":  "2026-05-04T19:16:05Z",
    "severity":  "MODERATE"
}
References

Affected packages

npm / n8n

Package

Name
n8n
View open source insights on deps.dev
Purl
pkg:npm/n8n

Affected ranges

Type
SEMVER
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
1.123.32

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-f6x8-65q6-j9m9/GHSA-f6x8-65q6-j9m9.json"

npm / n8n

Package

Name
n8n
View open source insights on deps.dev
Purl
pkg:npm/n8n

Affected ranges

Type
SEMVER
Events
Introduced
2.18.0
Fixed
2.18.1

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-f6x8-65q6-j9m9/GHSA-f6x8-65q6-j9m9.json"

npm / n8n

Package

Name
n8n
View open source insights on deps.dev
Purl
pkg:npm/n8n

Affected ranges

Type
SEMVER
Events
Introduced
2.0.0
Fixed
2.17.4

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-f6x8-65q6-j9m9/GHSA-f6x8-65q6-j9m9.json"