CVE-2026-85170: Improper Input Validation in n8n-io n8n

The vulnerability in n8n affects versions prior to 1.123.73, 2.35.4, and 2.36.2. It arises because the Gmail (v1) and Brevo nodes pass message content to the mail composer without verifying that it is a string. An authenticated user able to execute workflows can supply an expression that resolves to an object containing a path or href property. This can cause the mail composer to read local files accessible to the n8n process or fetch internal URLs (server-side request forgery), attaching the resulting content to outgoing messages.

An attacker with workflow execution privileges can exploit this vulnerability to read local files on the n8n host or perform SSRF attacks by fetching internal URLs. This can lead to unauthorized disclosure of sensitive information accessible to the n8n process. The vulnerability requires authenticated access and workflow execution capability, limiting exposure to trusted users or compromised accounts.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Users should upgrade to n8n versions 1.123.73, 2.35.4, or 2.36.2 or later once official fixes are released. Until then, restrict workflow execution permissions to trusted users and monitor for suspicious activity involving the Gmail (v1) and Brevo nodes.