CVE-2026-42235
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L
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.
Affected Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| n8n-io | n8n | < 1.123.32 | affected |
| n8n-io | n8n | >= 2.17.0, < 2.17.4 | affected |
| n8n-io | n8n | >= 2.18.0, < 2.18.1 | affected |
Weaknesses
- CWE-87: CWE-87: Improper Neutralization of Alternate XSS Syntax
- CWE-79: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
ADP Enrichment
CISA ADP Vulnrichment
- SSVC:
- Exploitation: none
- Automatable: no
- Technical Impact: total
References
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