Comprehensive Technical Analysis of EUVD-2026-8761
1. Vulnerability Assessment and Severity Evaluation
Vulnerability Description: The vulnerability in question, identified as EUVD-2026-8761, pertains to an expression sandbox escape in the n8n workflow automation tool, which can lead to Remote Code Execution (RCE). This vulnerability allows an attacker to break out of the sandbox environment and execute arbitrary code on the host system.
Severity Evaluation:
The Base Score of 9.4, according to CVSS version 4.0, indicates a critical severity level. The vector string CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H breaks down as follows:
- AV:N (Attack Vector: Network) - The vulnerability is exploitable over the network.
- AC:L (Attack Complexity: Low) - The attack requires minimal skill or resources.
- AT:N (Attack Technique: Network) - The attack technique involves network-based methods.
- PR:L (Privileges Required: Low) - The attacker needs low-level privileges to exploit the vulnerability.
- UI:N (User Interaction: None) - No user interaction is required for the attack to succeed.
- VC:H (Vulnerability Confidentiality: High) - The vulnerability significantly impacts confidentiality.
- VI:H (Vulnerability Integrity: High) - The vulnerability significantly impacts integrity.
- VA:H (Vulnerability Availability: High) - The vulnerability significantly impacts availability.
- SC:H (Scope Change: High) - The vulnerability allows for a significant change in scope.
- SI:H (Scope Integrity: High) - The scope integrity is highly impacted.
- SA:H (Scope Availability: High) - The scope availability is highly impacted.
2. Potential Attack Vectors and Exploitation Methods
Attack Vectors:
- Network-Based Attacks: Given the
AV:NandAT:Nparameters, attackers can exploit this vulnerability over the network, potentially targeting exposed n8n instances. - Low Privilege Requirement: The
PR:Lparameter indicates that attackers with minimal privileges can exploit this vulnerability, making it easier to execute.
Exploitation Methods:
- Expression Injection: Attackers can inject malicious expressions into the n8n workflow, which can escape the sandbox and execute arbitrary code on the host system.
- Remote Code Execution: Once the sandbox is escaped, attackers can execute commands, scripts, or other malicious code, leading to full system compromise.
3. Affected Systems and Software Versions
Affected Versions:
- n8n versions 2.0.0 to 2.9.3
- n8n version 2.10.0
- n8n versions prior to 1.123.22
Vendor:
- n8n-io
4. Recommended Mitigation Strategies
Immediate Actions:
- Patching: Upgrade to the latest patched versions of n8n. For versions 2.x, upgrade to 2.9.3 or higher. For version 2.10.x, upgrade to 2.10.1 or higher. For versions prior to 1.123.22, upgrade to 1.123.22 or higher.
- Network Segmentation: Isolate n8n instances from public networks to reduce the attack surface.
- Access Control: Implement strict access controls to limit who can interact with n8n workflows.
Long-Term Strategies:
- Regular Audits: Conduct regular security audits and vulnerability assessments.
- Monitoring: Implement continuous monitoring to detect and respond to suspicious activities.
- Security Training: Educate users and administrators on best practices for securing n8n instances.
5. Impact on European Cybersecurity Landscape
Regulatory Compliance:
- GDPR: Organizations using n8n must ensure that they comply with GDPR regulations, especially regarding data protection and breach reporting.
- NIS Directive: Critical infrastructure organizations must adhere to the Network and Information Systems (NIS) Directive, ensuring robust cybersecurity measures are in place.
Economic and Operational Impact:
- Downtime: RCE vulnerabilities can lead to significant downtime and operational disruptions.
- Data Breaches: Compromised systems can result in data breaches, leading to financial losses and reputational damage.
6. Technical Details for Security Professionals
Technical Analysis:
- Sandbox Escape Mechanism: The vulnerability allows attackers to escape the expression sandbox by injecting specially crafted expressions that bypass the sandbox's security mechanisms.
- Code Execution: Once out of the sandbox, attackers can execute arbitrary code with the privileges of the n8n process, potentially leading to full system compromise.
References:
Conclusion: The EUVD-2026-8761 vulnerability in n8n is critical and requires immediate attention. Organizations should prioritize patching affected systems and implementing robust security measures to mitigate the risk of exploitation. Continuous monitoring and regular security audits are essential to maintain a strong cybersecurity posture.