CVE-2026-56357Network attack vector

Workflow event spoofing via missing signature verification

Published Jun 22, 2026 · Updated Jun 22, 2026

Webhook forgery in the GitHub Webhook Trigger node in n8n before 1.123.15 and 2.5.0 allows remote attackers to spoof GitHub events. The node accepts POST bodies without validating GitHub's HMAC-SHA256 delivery signature and passes attacker-controlled event data into the workflow. Exploitation requires knowledge of an enabled workflow's webhook URL and causes that workflow to run with forged input and its configured downstream effects.

CVSS severity6.3
Medium
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Webhook forgery in the GitHub Webhook Trigger node in n8n before 1.123.15 and 2.5.0 allows remote attackers to spoof GitHub events. The node accepts POST bodies without validating GitHub's HMAC-SHA256 delivery signature and passes attacker-controlled event data into the workflow. Exploitation requires knowledge of an enabled workflow's webhook URL and causes that workflow to run with forged input and its configured downstream effects.

The record

CVE
CVE-2026-56357
Published
Jun 22, 2026
Updated
Jun 22, 2026
Vendor
n8n
Product
n8n
Classifications
CWE-290, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <1.123.15
  2. Affected versionversion=2.0.0 <2.5.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

n8n · n8nversion=0 <1.123.15; version=2.0.0 <2.5.0

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
6.3n8nCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-290Authentication Bypass by Spoofing
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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