CVE-2026-27577

Comprehensive Technical Analysis of CVE-2026-27577

1. Vulnerability Assessment and Severity Evaluation

CVE ID: CVE-2026-27577

Description: The vulnerability affects n8n, an open-source workflow automation platform. Prior to versions 2.10.1, 2.9.3, and 1.123.22, n8n is susceptible to command injection through crafted expressions in workflow parameters. This allows an authenticated user with workflow creation or modification permissions to execute unintended system commands on the host running n8n.

CVSS Score: 9.9

Severity Evaluation:

• Critical Severity: The CVSS score of 9.9 indicates a critical vulnerability. This high score is due to the potential for complete system compromise, including arbitrary command execution, which can lead to data breaches, system takeovers, and other severe impacts.
• Exploitability: The vulnerability requires authentication but can be exploited by any user with workflow creation or modification permissions, making it relatively easy to exploit within the context of authorized users.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Authenticated User Exploitation: An attacker with valid credentials and permissions to create or modify workflows can inject malicious expressions into workflow parameters.
• Internal Threats: Insider threats or compromised user accounts can exploit this vulnerability to escalate privileges or execute unauthorized commands.

Exploitation Methods:

• Command Injection: By crafting expressions that include system commands, an attacker can trigger unintended command execution on the host system.
• Payload Delivery: Malicious payloads can be embedded within workflow parameters, leading to remote code execution (RCE) and potential lateral movement within the network.

3. Affected Systems and Software Versions

Affected Versions:

• n8n versions prior to 2.10.1
• n8n versions prior to 2.9.3
• n8n versions prior to 1.123.22

Systems at Risk:

• Any system running the affected versions of n8n, including on-premises installations and cloud-based deployments.
• Environments where users have permissions to create or modify workflows, especially those with less stringent access controls.

4. Recommended Mitigation Strategies

Immediate Actions:

• Upgrade: Upgrade to n8n versions 2.10.1, 2.9.3, or 1.123.22 or later to remediate the vulnerability.
• Access Control: Limit workflow creation and editing permissions to fully trusted users only.
• Environment Hardening: Deploy n8n in a hardened environment with restricted operating system privileges and network access to reduce the impact of potential exploitation.

Long-Term Mitigations:

• Regular Audits: Conduct regular security audits and vulnerability assessments.
• Monitoring: Implement monitoring and logging to detect and respond to suspicious activities related to workflow modifications.
• User Training: Educate users on the risks associated with workflow creation and modification, emphasizing the importance of secure practices.

5. Impact on Cybersecurity Landscape

Immediate Impact:

• System Compromise: Organizations using affected versions of n8n are at risk of system compromise, data breaches, and unauthorized command execution.
• Operational Disruption: Exploitation can lead to operational disruptions, including service outages and data loss.

Long-Term Impact:

• Increased Awareness: This vulnerability highlights the importance of securing workflow automation platforms and the need for robust access controls.
• Best Practices: Encourages the adoption of best practices for securing open-source software and managing user permissions.

6. Technical Details for Security Professionals

Vulnerability Details:

• Expression Evaluation: The vulnerability resides in the expression evaluation mechanism of n8n, which fails to properly sanitize inputs, leading to command injection.
• Patch Information: The issues have been fixed in the following commits:
  • Commit 1479aab2d32fe0ee087f82b9038b1035c98be2f6
  • Commit 9e5212ecbc5d2d4e6f340b636a5e84be6369882e

References:

• n8n Security Overview
• GitHub Security Advisory GHSA-v98v-ff95-f3cp
• GitHub Security Advisory GHSA-vpcf-gvg4-6qwr

Conclusion: CVE-2026-27577 represents a critical vulnerability in n8n that requires immediate attention. Organizations should prioritize upgrading to the patched versions and implementing robust access controls to mitigate the risk of exploitation. This vulnerability underscores the importance of continuous monitoring and proactive security measures in protecting against command injection attacks.