Prototype pollution in n8n - #VU146799
Published: September 2, 2026
Vulnerability identifier: #VU146799
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-1321
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to improper control of dynamically managed code resources in workflow structure summary generation when processing a stored workflow submitted through the REST API. A remote user can submit a crafted workflow containing reserved keys such as __proto__ to cause a denial of service.
Only the Instance AI workflow summary code path is affected.
Affected software
n8n
Remediation
Install security update from vendor's website.
n8n - addressed in versions 2.37.7, 2.38.2