n8n before 1.123.83, 2.41.4, and 2.42.1 Unauthenticated Workflow Execution via Dynamic-Path Webhook Resolution

n8n before 1.123.83, 2.x before 2.41.4, and 2.42.x before 2.42.1 contains an authentication bypass because dynamic-path webhook resolution matched requests on the path alone, ignoring the server-generated identifier that is the URL's only unguessable component. Unauthenticated attackers can omit this identifier in requests to webhook, form, or MCP routes to execute workflows in unrelated projects under those projects' credentials.