n8n: Open Redirect in MCP OAuth Consent Flow
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 1.123.32, 2.17.4, 2.18.1
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
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.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- n8n-io n8n
fixed in 1.123.32; From 2.17.0 · fixed in 2.17.4; From 2.18.0 · fixed in 2.18.1
- n8nnpm
fixed in 1.123.32
- n8nnpm
From 2.18.0 · fixed in 2.18.1
- n8nnpm
From 2.0.0 · fixed in 2.17.4