Executive brief
n8n is a workflow automation tool used to connect various business applications. A security flaw was discovered where Google Service Account private keys were accidentally included in plain text within the headers of authentication tokens. If these tokens were captured via logs or network inspection, an attacker could use the exposed key to impersonate the service account and access or modify sensitive Google Cloud resources.
Technical details
A vulnerability in n8n's handling of Google Service Account credentials resulted in the full PEM private key being placed in the 'kid' (Key ID) field of JWT headers. Because JWT headers are Base64-encoded rather than encrypted, the private key is effectively stored in cleartext. An attacker with access to application logs, proxy logs, or network traffic containing these JWTs could extract the key to impersonate the service account. This issue affects n8n instances configured with Google Service Account credentials across several version ranges. Patches are available in versions 1.123.64, 2.29.8, and 2.30.1.
Affected products
- n8n-io n8n < 1.123.64, >= 2.0.0-rc.0, < 2.29.8, >= 2.30.0, < 2.30.1
Timeline
- 2026-07-08: disclosed: Initial report to n8n-io/n8n
- 2026-07-22: advisory: GitHub Advisory published