n8n is an open source workflow automation platform. Prior to versions 1.123.33 and 2.17.5, the dynamic-node-parameters endpoints did not verify whether the authenticated caller was authorized to use a supplied credential reference. An authenticated user with access to a shared workflow could supply a foreign credential ID in the request body, causing the backend to decrypt and use that credential in a helper execution path where the caller also controls the destination URL. This allowed the caller to force the backend to authenticate against attacker-controlled infrastructure using a credential belonging to another user, effectively exfiltrating a reusable API key. The issue is not limited to any single node type; any node that resolves credentials dynamically through these endpoints may be affected. This issue has been patched in versions 1.123.33, 2.17.5, and 2.18.0.
Exploitability
AV:NAC:LAT:NPR:LUI:NVulnerable System
VC:HVI:NVA:LSubsequent System
SC:LSI:LSA:L7.1/CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:L/SC:L/SI:L/SA:LAccess Control