CVE-2026-42230 json
n8n: Open Redirect in MCP OAuth Consent Flow
published 2026-04-29 6 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-27100 , GHSA-f6x8-65q6-j9m9
- cvss
- 6.1
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 7%
- public exploits
- 0
- none known
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.
Patch / fix
- npm n8n 1.123.32, 2.17.4, 2.18.1
- n8n n8n 1.123.32, 2.17.4, 2.18.1
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 6 mo ago
Exploit prediction
0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 5.1 | 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 |
| GitHub | 3.1 | 4.7 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N |
| CNA | 4.0 | 5.1 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| NVD | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | n8n | <1.123.32 >=2.18.0, <2.18.1 >=2.0.0, <2.17.4 |
1.123.32 2.18.1 2.17.4 |
Affected products
- n8n-io n8n
Classification
- Weakness
-
- CWE-601 URL Redirection to Untrusted Site
References
-
github.com
/n8n-io/n8n/security/advisories/GHSA-f6x8-65q6-j9m9
web, vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-42230
advisory
-
github.com
/n8n-io/n8n
package
Sources
- CVE List CVE-2026-42230
- GitHub Advisory GHSA-f6x8-65q6-j9m9
- NVD CVE-2026-42230
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.