CVE-2026-103245: n8n before 1.123.80, 2.39.6, and 2.40.1 Missing Webhook Signature Verification

Severity: medium (CVSS 5.3 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: 2026-10-01 · updated 2026-10-01
Weakness: CWE-347

Description

n8n versions before 1.123.80, from 2.0.0 before 2.39.6, and from 2.40.0 before 2.40.1 fail to verify the x-webflow-signature HMAC in the Webflow Trigger node webhook handler. Unauthenticated attackers can send forged webhook requests with attacker-controlled payloads to trigger workflows and manipulate downstream actions like record creation or API calls.

Affected products

n8n-io n8n: before 1.123.80; from 2.0.0 before 2.39.6; from 2.40.0 before 2.40.1 — fixed in 1.123.80, 2.39.6, 2.40.1

How to fix

Upgrade to a fixed version: n8n-io n8n 1.123.80, 2.39.6, 2.40.1. Check the vendor advisory for mitigations.

References

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