CVE-2026-65599: n8n before 1.123.64, 2.29.8, and 2.30.1 Credential Exposure via JWT Header
Impact When n8n was configured with a Google Service Account key, the full PEM private key was mistakenly placed in the JWT header's kid field (which should only have held a key identifier). Since JWT headers were Base64-encoded rather than encrypted, the 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.
Patches The issue has been fixed in n8n versions 1.123.64, 2.29.8, and 2.30.1. Users should upgrade to one of these versions or later to remediate the vulnerability.
Workarounds If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Avoid using Google Service Account credentials until the instance is patched. - Rotate any Google Service Account keys that may have been used with an affected n8n version. - Review proxy, load balancer, and application logs for JWT headers that may contain exposed key material and treat any such keys as compromised.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Other sources
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.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 2.29.8 - Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 2.30.1 - Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 1.123.64 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 1.123.64 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 2.29.8 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 2.30.1 - Compensating control
Avoid using Google Service Account credentials until the n8n instance is patched.
- Operational
Review proxy, load balancer, and application logs for JWT headers that may contain exposed key material; treat any such keys as compromised.
- Operational
Rotate any Google Service Account keys that may have been used with an affected n8n version.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-65599?
The severity of CVE-2026-65599 is classified as medium with a CVSS score of 5.1.
What impact does CVE-2026-65599 have on affected systems?
CVE-2026-65599 exposes the full PEM private key in the JWT header's 'kid' field, leading to potential credential misuse.
How do I fix CVE-2026-65599?
To fix CVE-2026-65599, upgrade n8n to versions 1.123.64, 2.29.8, or 2.30.1.
Which versions of n8n are vulnerable to CVE-2026-65599?
n8n versions before 1.123.64, 2.29.8, and 2.30.1 are vulnerable to CVE-2026-65599.
Is the JWT header in CVE-2026-65599 encrypted?
No, the JWT header in CVE-2026-65599 is Base64-encoded rather than encrypted, allowing for potential key recovery.