CVE-2026-56357 json
n8n - Webhook Forgery via Missing HMAC-SHA256 Signature Verification in GitHub Webhook Trigger
published 2026-02-26 8 mo ago modified 2026-07-18 3 mo ago also GHSA-mqpr-49jj-32rc , EUVD-2026-38377
- cvss
- 4.0
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 24%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- npm n8n 1.123.15, 2.5.0
- n8n n8n 1.123.15, 2.5.0
- github.com/n8n-io/n8n@a19347a commit
- github.com/n8n-io/n8n@afe3223 commit
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 4 mo ago
Exploit prediction
0.31% chance of exploitation in the next 30 days, higher than 24% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.3 | 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 |
| CNA | 3.1 | 4.0 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N |
| CNA | 4.0 | 6.3 | 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 |
| NVD | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
| GitHub | 3.1 | 4.0 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | n8n | <1.123.15 >=2.0.0, <2.5.0 |
1.123.15 2.5.0 |
Affected products
- n8n n8n
Classification
- Weakness
-
- CWE-290 Authentication Bypass by Spoofing
References
-
github.com
/n8n-io/n8n/commit/a19347a6bc9a96d5065ac77d25a811e46178c578
web
-
github.com
/n8n-io/n8n/commit/afe322325502f448b33bff1db1575e4447c28a36
web
-
github.com
/n8n-io/n8n/security/advisories/GHSA-mqpr-49jj-32rc
vendor-advisory, web
-
vulncheck.com
/advisories/n8n-webhook-forgery-via-missing-hmac-sha256-signature-verification-in-github-webhook-trigger
third-party-advisory, web
-
nvd.nist.gov
/vuln/detail/CVE-2026-56357
advisory
-
github.com
/n8n-io/n8n
package
Sources
- CVE List CVE-2026-56357
- GitHub Advisory GHSA-mqpr-49jj-32rc
- NVD CVE-2026-56357
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