CVE-2026-56357

medium

Description

n8n before 1.123.15 and 2.5.0 contains a webhook forgery vulnerability in the GitHub Webhook Trigger node that fails to implement HMAC-SHA256 signature verification. Attackers who know the webhook URL can send unsigned POST requests to trigger workflows with arbitrary data, spoofing GitHub webhook events.

References

Advisories

https://www.vulncheck.com/advisories/n8n-webhook-forgery-via-missing-hmac-sha256-signature-verification-in-github-webhook-trigger

https://github.com/n8n-io/n8n/security/advisories/GHSA-mqpr-49jj-32rc

Details

Source: Mitre, NVD

Published: 2026-06-22

Updated: 2026-06-24

Risk Information

CVSS v2

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 5.3

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Severity: Medium

CVSS v4

Base Score: 6.3

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N

Severity: Medium

EPSS

EPSS: 0.00186