n8n before 2.20.0 contains a credential exfiltration vulnerability in the POST /rest/dynamic-node-parameters/options endpoint that allows authenticated users to bypass Allowed H...
Date: 2026-06
Affected: n8n/n8n
Attack vector: data-exfiltration
Category: vulnerability-disclosure
Severity: Critical
CVE: CVE-2026-56348
CWE: CWE-918
CVSS: 9.1 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L)

n8n before 2.20.0 contains a credential exfiltration vulnerability in the POST /rest/dynamic-node-parameters/options endpoint that allows authenticated users to bypass Allowed HTTP Request Domains restrictions. Attackers with credential access can cause the n8n server to issue HTTP requests with credentials to unauthorized hosts, exfiltrating sensitive authentication data.


Mitigations:

Architectural layers (MAESTRO):