CVE-2026-56357

mediumpriority · track · 21EPSS 0.003 · 24 %ileDEEUNLUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.31% (24th) EPSS
CVSS 5.3 · medium
Is it mine?
8 products
Check your exposure
Who says so?
6 sources
cnnvd · enisa_euvd · cert_bund · ncsc_nl

EPSS · scored 2026-10-27

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.

01

cvss

Technical severity, 0–10. One row per scoring source.

6.3
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 1.7–6.3

v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 1.4
v3.14mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:Nsecondary · disclosure@vulncheck.comexploitability 2.2 · impact 1.4
v3.14mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:Nsecondary · OSV
v3.14mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:Nsecondary · NCSC-NL NL
v4.01.7lowCVSS: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:U/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:Xsecondary · CVSS-BT (t0sche)
v4.06.3mediumCVSS: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:Xsecondary · disclosure@vulncheck.com
v4.06.3mediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:Nsecondary · ENISA EU
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-290USCWE-290USCWE-290US
04

affected products (8)

Products and version ranges known to be affected.

05

advisories (3)

Vendor and ecosystem advisories describing this.

  • NCSC-2026-0248Kwetsbaarheden verholpen in n8n workflow automation platformNL2026-07-17csaf · ncsc_nlNL

    n8n heeft meerdere kwetsbaarheden verholpen in het n8n workflow automation platform, specifiek in versies voor 2.10.1, 2.9.3, 1.123.22 en andere gerelateerde releases.

  • WID-SEC-W-2026-0532n8n: Mehrere SchwachstellenDeutsch2026-02-25csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in n8n ausnutzen, um beliebigen Programmcode auszuführen, um Sicherheitsvorkehrungen zu umgehen, um Daten zu manipulieren, um einen SQL-Injection Angriff durchzuführen, und um einen Cross-Site Scripting Angriff durchzuführen.

  • GHSA-mqpr-49jj-32rcn8n: Webhook Forgery on Github Webhook Trigger2026-02-26ghsa · osvUS

    ## Impact An attacker who knows the webhook URL of a workflow using the GitHub Webhook Trigger node could send unsigned POST requests and trigger the workflow with arbitrary data. The node did not implement the HMAC-SHA256 signature verification that GitHub provides to authenticate webhook deliveries, allowing any party to spoof GitHub webhook events. ## Patches The issue has been fixed in n8n versions 2.5.0 and 1.123.15. Users should upgrade to one of these versions or later to remediate the vulnerability. ## Workarounds If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Limit workflow creation and editing permissions to fully trusted users only. - Restrict network access to the n8n webhook endpoint to known GitHub webhook IP ranges. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

06

also known as (2)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdcert_bundncsc_nlnvdosvNVDCVE.orgMITRE
published 2026-06-22modified 2026-06-24
08

references (6)

External citations — patches, advisories, analysis.

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