CVE-2026-86074: n8n Instance AI credential setup SSRF via unvalidated probe URL

Executive brief

n8n is a workflow automation platform that allows users to connect applications and automate business processes. The Instance AI credential setup feature accepted credential test URLs without validating they matched the workflow node's origin, enabling attackers to redirect authentication requests to arbitrary destinations. Exploitation required an attacker to inject a malicious URL into the setup flow, allowing exfiltration of API credentials or redirection of authenticated requests to attacker-controlled servers.

Technical details

This is a server-side request forgery (SSRF) vulnerability in n8n's Instance AI credential setup flow. The vulnerable component failed to validate that credential test/verification probe URLs matched the workflow node's origin before making authenticated requests or following redirects. An attacker could inject an arbitrary URL into the credential setup flow, causing the n8n server to send authenticated requests to a malicious destination, potentially exfiltrating third-party API credentials or other sensitive data. The attack requires user interaction (an authenticated user must manually inject the attacker URL into the setup flow). The fix derives the credential destination from the node's own URL and restricts all authenticated requests, redirects, and probes to that origin.

Affected products

• n8n n8n >= 2.38.0, < 2.38.2; < 2.37.7

Timeline

• 2026-09-02: disclosed
• 2026-09-02: patched: Fixes released in n8n 2.38.2 and 2.37.7

References

• https://api.github.com/users/nlgbao1340
• https://github.com/nlgbao1340
• https://api.github.com/users/nlgbao1340/gists%7B/gist_id%7D
• https://api.github.com/users/nlgbao1340/repos
• https://avatars.githubusercontent.com/u/125201610?v=4
• https://api.github.com/users/nlgbao1340/events%7B/privacy%7D