CVE-2026-65599: n8n before 1.123.64, 2.29.8, and 2.30.1 Credential Exposure via JWT Header

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-22 · updated 2026-10-29
Weakness: CWE-312

Description

n8n versions before 1.123.64, 2.29.8, and 2.30.1 contain a credential exposure vulnerability: when configured with a Google Service Account key, the full PEM private key was mistakenly placed in the JWT header's kid field (intended only for a key identifier). Because JWT headers are Base64-encoded rather than encrypted, the private key could be recovered by anything that logged or inspected the JWT. An attacker who obtained the key could impersonate the service account and access or modify any Google Cloud resource it was authorized to use. Only instances using Google Service Account credentials are affected.

Affected products

n8n-io n8n: before 1.123.64; from 2.0.0 before 2.29.8; 2.30.0 (and their updates) — fixed in 1.123.64, 2.29.8
n8n-io n8n: before 1.123.64 — fixed in 1.123.64

How to fix

Upgrade to a fixed version: n8n-io n8n 1.123.64, 2.29.8; n8n-io n8n 1.123.64. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-65599 or the next vulnerability affects your stack