n8n: Webhook Forgery on Github Webhook Trigger
Date: 2026-02
Affected: npm/n8n, npm/n8n
Attack vector: other
Category: vulnerability-disclosure
Severity: Medium
CWE: CWE-290
CVSS: 4 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N)

## Impact An attacker who knows the webhook URL of a workflow using the GitHub Webhook Trigger node could send unsigned POST requests and trigger the workflow with arbitrary data. The node did not implement the HMAC-SHA256 signature verification that GitHub provides to authenticate webhook deliveries, allowing any party to spoof GitHub webhook events. ## Patches The issue has been fixed in n8n versions 2.5.0 and 1.123.15. 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: - Limit workflow creation and editing permissions to fully trusted users only. - Restrict network access to the n8n webhook endpoint to known GitHub webhook IP ranges. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.


Mitigations:

Architectural layers (MAESTRO):