How can you patch the critical CVEs found in n8n self-hosted instances?

Is your automation workflow safe from the recent n8n security breaches?

Recent security audits have uncovered severe vulnerabilities within the n8n workflow automation platform. For organizations relying on n8n to connect disparate apps and services—including those integrating AI agents—these flaws present immediate risks. Multiple critical vulnerabilities (CVEs) have surfaced in rapid succession, exposing both self-hosted and cloud environments to potential compromise.

If you manage an n8n instance, immediate action is required to secure your data infrastructure.

Understanding the Platform Risk

n8n is a node-based workflow automation tool headquartered in Berlin. It allows users to design directed graphs where data flows between services like Slack, Google Sheets, and custom databases. Built on Node.js and TypeScript, it offers powerful horizontal scaling capabilities. However, its architecture, which grants extensive system access to execute complex tasks, also creates a significant attack surface if not properly sandboxed.

The recent discovery of three specific vulnerabilities indicates a pattern of weakness in how the platform isolates execution environments and handles authentication.

Critical Vulnerability Breakdown

The “Ni8mare” Flaw: Unauthenticated File Access (CVE-2026-21858)

Severity: Critical (CVSS 10.0)
Status: Patched in v1.121.0

Disclosed on January 7, 2026, by FieldEffekt, this is the most dangerous flaw currently affecting the ecosystem. It received the maximum severity score because it requires no authentication.

• The Mechanism: An attacker can exploit this flaw to access files on the host system without logging in.
• The Impact: Complete system compromise. Because n8n often holds API keys and credentials for other services, a breach here allows attackers to pivot into other parts of your infrastructure.
• Affected Versions: Self-hosted instances from v1.65.0 up to v1.121.0.
• Immediate Fix: Upgrade to version 1.121.0 or later immediately. If an update is impossible, you must disable public access to the instance.

Remote Code Execution via Git Node (CVE-2026-21877)

Severity: Critical (CVSS 9.9)
Status: Patched in v1.121.3

Publicly disclosed on January 6, 2026, this Remote Code Execution (RCE) vulnerability affects both self-hosted and cloud instances.

• The Mechanism: An authenticated attacker can leverage the Git node functionality to run malicious code on the server.
• The Impact: This grants the attacker control over the n8n service, allowing them to manipulate workflows, exfiltrate data, or disrupt operations.
• Affected Versions: Versions 0.121.2 and earlier.
• Mitigation: Update to v1.121.3. As a temporary measure, administrators can disable the Git node and strictly limit access permissions for untrusted users.

Sandbox Escape in Python Nodes (CVE-2025-68668)

Severity: Critical (CVSS 9.8)
Status: Patched in v2.0.0

Disclosed in late December 2025, this vulnerability targets the Pyodide-based Python code node.

• The Mechanism: The flaw allows a user to escape the Pyodide sandbox environment.
• The Impact: An authenticated user with workflow creation rights can execute arbitrary commands on the host system with the same privileges as the main n8n process.
• Affected Versions: Version 1.0.0 through 2.0.0.
• Fix: Upgrade to n8n version 2.0.0.

Strategic Recommendations for Administrators

The convergence of these vulnerabilities creates a “perfect storm” for automation platforms. If you utilize n8n, specifically for AI agent orchestration, the risk profile is elevated due to the sensitive nature of the data being processed.

Steps to secure your environment:

1. Audit Your Version: Check your current n8n version immediately. If you are running any version prior to 1.121.3 (or 2.0.0 for the Python fix), you are likely vulnerable.
2. Apply Patches: Prioritize updating to the latest stable release. The patch for CVE-2026-21858 (Ni8mare) is the most urgent due to its unauthenticated nature.
3. Restrict Access: Until patches are applied, ensure your n8n instance is not exposed to the public internet. Use a VPN or strict IP whitelisting.
4. Review User Privileges: Since two of these exploits require authentication, strictly limit who has “Editor” or “Admin” rights within your workflows.