CVE-2026-56357
n8n - Webhook Forgery via Missing HMAC-SHA256 Signature Verification in GitHub Webhook Trigger
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.
INFO
Published Date :
June 22, 2026, 10:16 p.m.
Last Modified :
June 24, 2026, 4:47 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update n8n to version 1.123.15 or later.
- Configure webhook signing for security.
- Validate incoming webhook signatures.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-56357.
| URL | Resource |
|---|---|
| https://github.com/n8n-io/n8n/security/advisories/GHSA-mqpr-49jj-32rc | Vendor Advisory |
| https://www.vulncheck.com/advisories/n8n-webhook-forgery-via-missing-hmac-sha256-signature-verification-in-github-webhook-trigger | Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-56357 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-56357
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-56357 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-56357 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jun. 24, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Added CPE Configuration OR *cpe:2.3:a:n8n:n8n:*:*:*:*:community:node.js:*:* versions up to (excluding) 1.123.15 *cpe:2.3:a:n8n:n8n:*:*:*:*:community:node.js:*:* versions from (including) 2.0.0 up to (excluding) 2.5.0 *cpe:2.3:a:n8n:n8n:*:*:*:*:enterprise:node.js:*:* versions up to (excluding) 1.123.15 *cpe:2.3:a:n8n:n8n:*:*:*:*:enterprise:node.js:*:* versions from (including) 2.0.0 up to (excluding) 2.5.0 Added Reference Type VulnCheck: https://github.com/n8n-io/n8n/security/advisories/GHSA-mqpr-49jj-32rc Types: Vendor Advisory Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/n8n-webhook-forgery-via-missing-hmac-sha256-signature-verification-in-github-webhook-trigger Types: Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 23, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-56357', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-23T14:24:49.624521Z'} -
New CVE Received by [email protected]
Jun. 22, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'n8n', 'product': 'n8n', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '1.123.15', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '1.123.15', 'versionType': 'semver'}, {'status': 'affected', 'version': '2.0.0', 'lessThan': '2.5.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '2.5.0', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/n8n', 'defaultStatus': 'unaffected'}] Added 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. Added CVSS V4.0 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 Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N Added CWE CWE-290 Added Reference https://github.com/n8n-io/n8n/security/advisories/GHSA-mqpr-49jj-32rc Added Reference https://www.vulncheck.com/advisories/n8n-webhook-forgery-via-missing-hmac-sha256-signature-verification-in-github-webhook-trigger