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TI-2026-30556 Aliases CVE-2026-42235GHSA-537j-gqpc-p7fq

n8n: XSS via MCP OAuth client

Priority MEDIUM 40CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Active
Attack complexity
Low
Attack requirements
Present
Impact type
Cross-site scripting
Confidentiality · integrity · availability
High · High · Low
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-79.

Summary

n8n is an open source workflow automation platform. Prior to versions 1.123.32, 2.17.4, and 2.18.1, an unauthenticated attacker could register a malicious MCP OAuth client with a crafted client_name. If a victim user authorized the OAuth consent dialog and a second user subsequently revoked that access, a toast notification would render the injected script. Clicking the link would execute arbitrary JavaScript in the victim's authenticated n8n browser session, enabling credential and session token theft, workflow manipulation, or privilege escalation. This issue has been patched in versions 1.123.32, 2.17.4, and 2.18.1.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00332 26th percentileScored 2026-11-07
Fix Fixed n8n (n8n-io): 1.123.32, 2.17.4, 2.18.1n8n (npm): 1.123.32, 2.18.1, 2.17.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
n8nn8nbefore 1.123.32; 2.17.0 to before 2.17.4; 2.18.0 to before 2.18.11.123.32, 2.17.4, 2.18.1Patch availableCNA
—n8n (npm)before 1.123.321.123.32Patch availableGHSA-537j-gqpc-p7fq
—n8n (npm)2.18.0 to before 2.18.12.18.1Patch availableGHSA-537j-gqpc-p7fq
—n8n (npm)2.17.0 to before 2.17.42.17.4Patch availableGHSA-537j-gqpc-p7fq
  • n8n Vendorn8n Affected before 1.123.32; 2.17.0 to before 2.17.4; 2.18.0 to before 2.18.1 Fixed in 1.123.32, 2.17.4, 2.18.1 Patch available CNA
  • n8n (npm) Vendor— Affected before 1.123.32 Fixed in 1.123.32 Patch available GHSA-537j-gqpc-p7fq
  • n8n (npm) Vendor— Affected 2.18.0 to before 2.18.1 Fixed in 2.18.1 Patch available GHSA-537j-gqpc-p7fq
  • n8n (npm) Vendor— Affected 2.17.0 to before 2.17.4 Fixed in 2.17.4 Patch available GHSA-537j-gqpc-p7fq

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:n8n:n8n:*:*:*:*:enterprise:node.js:*:*before 1.123.32; 2.17.0 to before 2.17.4Vulnerablen8n
cpe:2.3:a:n8n:n8n:2.18.0:*:*:*:enterprise:node.js:*:*2.18.0Vulnerablen8n
  • cpe:2.3:a:n8n:n8n:*:*:*:*:enterprise:node.js:*:* Versions before 1.123.32; 2.17.0 to before 2.17.4 Vulnerable ·n8n
  • cpe:2.3:a:n8n:n8n:2.18.0:*:*:*:enterprise:node.js:*:* Versions 2.18.0 Vulnerable ·n8n

Remediation

  • Fix · CNA n8n (n8n-io) Fixed in 1.123.32, 2.17.4, 2.18.1
  • Fix · GHSA-537j-gqpc-p7fq n8n (npm) Fixed in 1.123.32 Advisory →
  • Fix · GHSA-537j-gqpc-p7fq n8n (npm) Fixed in 2.18.1 Advisory →
  • Fix · GHSA-537j-gqpc-p7fq n8n (npm) Fixed in 2.17.4 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-42235
  2. 2026-10-03 Alias added: GHSA-537j-gqpc-p7fq

References

Advisory 2

Other 1

  • TI-2025-42131 n8n Vulnerable to Remote Code Execution via Expression Injection KEVCVSS 3.1CRITICAL 10.0
  • TI-2026-17560 n8n Vulnerable to Unauthenticated File Access via Improper Webhook Request Handling CVSS 3.1CRITICAL 10.0
  • TI-2026-01167 Authenticated users can bypass the Expression sandbox mechanism to achieve full remote… CVSS 3.1CRITICAL 9.9
  • TI-2026-00644 Sandbox escape in n8n Python task runner allows for arbitrary code execution on the underlying host. CVSS 3.1CRITICAL 9.9
  • TI-2025-35293 An arbitrary file upload vulnerability in the Chat Trigger component of N8N v1.95.3… CVSS 3.1HIGH 8.8
  • TI-2023-12275 The n8n package 0.218.0 for Node.js allows Escalation of Privileges. CVSS 3.1HIGH 8.8
See all 178 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences