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...

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Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-q5xf-xhwf-cwqf.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...

CVE-2026-65594

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 was introduced does not verify that the authenticated user has access to the workflow referenced as the OAuth resource. On instances with at least one active MCP Server Trigger...

CVE-2026-65594

n8n (versions affected: before 2.29.8 and 2.30.x before 2.30.1; affected since 2.27.0) has an OAuth 2.1 flow where authentication does not verify that the user has access to the referenced workflow used as the OAuth resource. On systems with an active MCP Server Trigger workflow configured for n8...

CVE-2026-65594 n8n before 2.30.1 Missing OAuth Authorization Check

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 was introduced does not verify that the authenticated user has access to the workflow referenced as the OAuth resource. On instances with at least one active MCP Server Trigger...

CVE-2026-65594 n8n before 2.30.1 Missing OAuth Authorization Check

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 was introduced does not verify that the authenticated user has access to the workflow referenced as the OAuth resource. On instances with at least one active MCP Server Trigger...

CVE-2026-65594

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 was introduced does not verify that the authenticated user has access to the workflow referenced as the OAuth resource. On instances with at least one active MCP Server Trigger...

PT-2026-63352

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 was introduced does not verify that the authenticated user has access to the workflow referenced as the OAuth resource. On instances with at least one active MCP Server Trigger...