Missing Authentication for Critical Function in n8n - #VU137156
Published: July 8, 2026
Vulnerability identifier: #VU137156
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-306
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper access control in the DELETE /${restEndpoint}/test-webhook/:id endpoint when handling unauthenticated requests. A remote attacker can send a crafted request with a known workflow ID to cause a denial of service.
The impact is limited to disrupting in-progress test sessions. Production webhooks, persistent workflow state, and stored data are not affected.
Affected software
n8n
Remediation
Install security update from vendor's website.
n8n - addressed in versions 2.27.4, 2.28.0