# CVE-2026-56357: n8n - Webhook Forgery via Missing HMAC-SHA256 Signature Verification in GitHub Webhook Trigger

> CVE-2026-56357: n8n - Webhook Forgery via Missing HMAC-SHA256 Signature Verification in GitHub Webhook Trigger. CVSS 4.0 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-56357
Last updated: 2026-06-24T16:47:01Z

- Published: 2026-06-22 21:04 UTC · Updated: 2026-06-24 16:47 UTC · Assigner: VulnCheck
- CVSS: 4.0 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N
- EPSS: 0.31%, 24th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-290

## 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.

## Affected vendors and products

- n8n: n8n

## Tracked companies

- [n8n](https://rewindex.com/company/n8n.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-56357)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-56357)
- [https://github.com/n8n-io/n8n/security/advisories/GHSA-mqpr-49jj-32rc](https://github.com/n8n-io/n8n/security/advisories/GHSA-mqpr-49jj-32rc)
- [https://www.vulncheck.com/advisories/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)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-56357 · Markdown: https://rewindex.com/cve/CVE-2026-56357.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-56357 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:15:40.824Z