CVE-2026-56357 PUBLISHED

n8n - Webhook Forgery via Missing HMAC-SHA256 Signature Verification in GitHub Webhook Trigger

Assigner: VulnCheck
Reserved: 20.06.2026 Published: 22.06.2026 Updated: 23.06.2026

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.

CVSS Vector: 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
CVSS Score: 6.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	Low	Integrity	Low
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N
CVSS Score: 4

Attack Vector	Network	Scope	Changed
Attack Complexity	High	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	Low
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	n8n
Product	n8n
Versions	Default: unaffected affected from 0 to 1.123.15 (excl.) Version 1.123.15 is unaffected affected from 2.0.0 to 2.5.0 (excl.) Version 2.5.0 is unaffected

CVE-2026-56357 PUBLISHED

n8n - Webhook Forgery via Missing HMAC-SHA256 Signature Verification in GitHub Webhook Trigger

Metrics

Product Status

Credits

References

Problem Types