CVE-2026-72768 in n8n
Summary
by MITRE • 08/11/2026
n8n versions before 2.32.1 contain a server-side request forgery protection bypass vulnerability in the MCP Client node that allows authenticated users to bypass SSRF protections. Attackers can craft workflows that send requests to internal or blocked hosts without routing through SSRF protection, exposing internal services and reading responses back through the workflow.
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Analysis
by VulDB Data Team • 08/11/2026
The vulnerability identified in n8n versions prior to 2.32.1 represents a critical server-side request forgery protection bypass that specifically targets the MCP Client node functionality. This flaw allows authenticated users to circumvent established security measures designed to prevent unauthorized access to internal network resources. The vulnerability operates at the application layer where the SSRF protections should normally validate and control outgoing requests from the n8n workflow engine, but instead permits maliciously crafted workflows to bypass these safeguards entirely.
The technical implementation of this vulnerability stems from insufficient input validation within the MCP Client node's request handling mechanism. When users create workflows that utilize this node, the system should typically enforce strict controls over destination addresses and protocols to prevent access to internal systems or restricted network zones. However, the flaw in the code allows crafted payloads to bypass these validation checks, enabling requests to be routed directly to internal hosts or blocked IP addresses without proper authorization. This occurs because the security controls are either inadequately implemented or can be circumvented through specific parameter manipulation within the workflow configuration.
The operational impact of this vulnerability extends beyond simple unauthorized network access, as it fundamentally undermines the security boundaries that protect internal infrastructure from external threats. Attackers who can authenticate to the n8n system can leverage this vulnerability to enumerate internal services, potentially gaining access to sensitive systems that would normally be isolated from public networks. The exposure includes not only direct service access but also the ability to read responses back through the workflow execution environment, creating a complete data exfiltration and reconnaissance capability. This represents a significant risk to organizations that rely on n8n for automation workflows, as it could enable attackers to map internal network topologies and identify vulnerable services.
Organizations using affected versions of n8n should immediately implement mitigations including updating to version 2.32.1 or later where the vulnerability has been addressed through proper input validation and request routing controls. Additional protective measures include implementing network segmentation to isolate n8n instances from critical internal systems, enforcing strict access controls on workflow creation capabilities, and monitoring for unusual outbound request patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-918 which addresses server-side request forgery issues, and maps to ATT&CK technique T1071.004 for application layer protocol tunneling. Security teams should also consider implementing network-based controls such as firewalls and proxy configurations to limit outbound connectivity from n8n instances, while conducting thorough audits of existing workflows to identify any potential exploitation vectors that may have been previously overlooked.