n8n: Member-Level Users Can Execute Other Users' MCP Server Trigger Workflows via Missing OAuth Authorization Check

Impact The OAuth 2.1 consent and token-issuance flow introduced in n8n 2.27.0 does not verify that the authenticated user has access to the workflow referenced as the OAuth resource. A member-level user can register an OAuth client, self-approve consent for another user's n8n OAuth2-protected MCP...

Incorrect Authorization

Overview @n8n/n8n-nodes-langchain is a Affected versions of this package are vulnerable to Incorrect Authorization in the OAuth 2.1 authorization. An attacker can gain unauthorized access to another user's workflow and execute it with the owner's credentials by registering an OAuth client and...

GHSA-5VFW-JC4P-FJ39 Duplicate Advisory: Member-Level Users Can Execute Other Users' MCP Server Trigger Workflows via Missing OAuth Authorization Check

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-q5xf-xhwf-cwqf. This link is maintained to preserve external references. Original Description n8n before 2.29.8 and 2.30.x before 2.30.1 affected from 2.27.0, when the OAuth 2.1 consent and token-issuance flow w...

Duplicate Advisory: Member-Level Users Can Execute Other Users' MCP Server Trigger Workflows via Missing OAuth Authorization Check

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-q5xf-xhwf-cwqf. This link is maintained to preserve external references. Original Description n8n before 2.29.8 and 2.30.x before 2.30.1 affected from 2.27.0, when the OAuth 2.1 consent and token-issuance flow w...