CVE-2026-42235
HIGH EPSS 25.0%
Published May 4, 20261mo ago · Modified Jun 17, 20261w ago
8.8 CVSS 4.0
Published May 4, 2026 1mo ago
Last Modified Jun 17, 2026 1w ago
Description
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.
CVSS Details
Base Score
Exploitability
Impact
Vector string
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/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 Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction A
Scope X
Threat Intelligence
EPSS Exploit Probability
25.0% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
Weaknesses 2
CWE-79 Cross-site Scripting Injection
CWE-87
Affected Products 3
References 1
- github.com https://github.com/n8n-io/n8n/security/advisories/GHSA-537j-gqpc-p7fq
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.