CVE-2026-56357

Name: CVE-2026-56357
Creator: NVD / NIST
Published: 2026-06-22T22:16:52.51+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.3/10EPSS 0.19%

Last modified Jun 24, 2026

CVE-2026-56357 is a medium-severity vulnerability rated 6.3/10 on the CVSS scale. 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.. EPSS estimates a 0.19% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

5.3/10

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

CVSS 4.0

6.3/10

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

EPSS Probability

0.19%

8.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-290

Affected Software

Vendor	Product	Versions
N8n	N8n	< 1.123.15
N8n	N8n	>= 2.0.0, < 2.5.0

References

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

Timeline

Published: Jun 22, 2026
Last Modified: Jun 24, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-56357?

How severe is CVE-2026-56357?

CVE-2026-56357 has a CVSS score of 6.3/10 (MEDIUM severity). The EPSS model estimates a 0.19% probability of exploitation in the next 30 days.

How do I fix CVE-2026-56357?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-56357?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST