CVE-2026-103246: n8n before 2.39.6 and 2.40.x before 2.40.1 Credential Disclosure via Node-Tool Introspection

Severity: high (CVSS 7.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-01 · updated 2026-10-06
Weakness: CWE-639

Description

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 products

n8n-io n8n: before 2.39.6; from 2.40.0 before 2.40.1 — fixed in 2.39.6, 2.40.1

How to fix

Upgrade to a fixed version: n8n-io n8n 2.39.6, 2.40.1. Check the vendor advisory for mitigations.

References

https://github.com/n8n-io/n8n/security/advisories/GHSA-9rhv-fhr8-7q5r
https://www.vulncheck.com/advisories/n8n-before-2.39.6-and-2.40-x-before-2.40.1-credential-disclosure-via-node-tool-introspection

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