CVE-2026-56357 | n8n before 1.123.15 and 2.5.0 contains a webhook forgery vul… | CVSS 4.0 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.

Metadata

CVE ID: CVE-2026-56357
State: PUBLISHED
Assigner: VulnCheck
Reserved: 2026-06-20 21:16 UTC
Published: 2026-06-22 21:04 UTC
Last updated: 2026-06-22 21:04 UTC
Primary CWE: CWE-290
Authentication Bypass by Spoofing
Vendor / Product: n8n / n8n
Sources: cve.org · NVD

Severity & Metrics

4.0 MEDIUM CVSS 3.1

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

Affected products (1)

Vendor	Product	Platform	Versions
n8n	n8n	—	0 < 1.123.15, 1.123.15, 2.0.0 < 2.5.0, 2.5.0

Weakness (CWE)

CWE	Source	Description
CWE-290	cna	Authentication Bypass by Spoofing

CVSS scores (2)

Score	Severity	Version	Source	Vector
6.3	MEDIUM	4.0	cna	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
4.0	MEDIUM	3.1	cna	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N

References (2)

GitHub Security Advisory (GHSA-mqpr-49jj-32rc) https://github.com/n8n-io/n8n/security/advisories/GHSA-mqpr-49jj-32rc
VulnCheck Advisory: n8n - Webhook Forgery via Missing HMAC-SHA256 Signature Verification in GitHub Webhook Trigger https://www.vulncheck.com/advisories/n8n-webhook-forgery-via-missing-hmac-sha256-signature-verification-in-github-webhook-trigger