n8n vulnerability

n8n versions before 2.39.6 and 2.40.0 before 2.40.1 fail to validate credential ownership during inline agent node-tool introspection. Attackers can reference arbitrary credential IDs to decrypt and exfiltrate plaintext secrets to attacker-controlled hosts without ownership verification.

Published 1 Oct 2026Updated 5 Oct 20262 sources
CVSS 8.3

What happened

n8n versions before 2.39.6 and 2.40.0 before 2.40.1 fail to validate credential ownership during inline agent node-tool introspection. Attackers can reference arbitrary credential IDs to decrypt and exfiltrate plaintext secrets to attacker-controlled hosts without ownership verification.

Affected versions

n8n: before 2.39.6 (semver); 2.40.0 through before 2.40.1 (semver) Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.