CVE-2026-56357

MEDIUM EPSS 8.3%

Published Jun 22, 20261w ago · Modified Jun 23, 20261w ago

6.3 CVSS 4.0

Medium

Published Jun 22, 2026 1w ago

Last Modified Jun 23, 2026 1w ago

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.

CVSS Details

Base Score

6.3

Exploitability

—

Impact

—

Vector string

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector Network

Attack Complexity Low

Privileges Required None

User Interaction None

Scope X

Threat Intelligence

EPSS Exploit Probability

8.3% percentile

Exploit & Patch Status

No Known Exploit

No Patch Available

Weaknesses 1

CWE-290

References 2

github.com https://github.com/n8n-io/n8n/security/advisories/GHSA-mqpr-49jj-32rc
vulncheck.com https://www.vulncheck.com/advisories/n8n-webhook-forgery-via-missing-hmac-sha256-signature-verification-in-github-webhook-trigger

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.