The vulnerability identified as CVE-2026-21893 affects the n8n open source workflow automation platform, specifically versions from 0.187.0 up to 1.120.3. The flaw is an OS command injection (CWE-78) stemming from improper neutralization of special characters in the community package installation functionality. This allows an authenticated user with administrative privileges to inject and execute arbitrary system commands on the host operating system. The vulnerability does not require user interaction but does require high privileges (administrative access) to exploit. The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H) reflects network attack vector, low attack complexity, no user interaction, but requiring high privileges, and with high impact on confidentiality, integrity, and availability. The vulnerability could lead to full system compromise, data theft, or disruption of automation workflows. The issue was publicly disclosed and patched in version 1.120.3 of n8n. No known exploits have been reported in the wild yet, but the critical severity demands immediate attention. The root cause is insufficient input validation and sanitization in the command execution path related to package installation, allowing injection of malicious OS commands. This vulnerability highlights the risks of granting administrative permissions broadly in automation platforms and the importance of secure coding practices for command execution features.

For European organizations, the impact of CVE-2026-21893 can be severe, especially for those relying on n8n for critical automation workflows in IT operations, business processes, or industrial control systems. Successful exploitation could allow attackers to execute arbitrary commands on the host system, potentially leading to full system compromise, data exfiltration, disruption of services, or lateral movement within the network. This could affect confidentiality, integrity, and availability of sensitive data and operational processes. Organizations with multiple administrators or shared admin credentials face increased risk of insider threats or credential compromise leading to exploitation. The automation nature of n8n means that compromised hosts could be used to propagate malicious commands or disrupt automated business-critical tasks. Given the high CVSS score and the network-exploitable nature of the vulnerability, the threat is significant for enterprises, government agencies, and critical infrastructure operators in Europe using n8n. The lack of known exploits in the wild currently reduces immediate risk but does not eliminate the potential for future attacks, especially as threat actors often target automation platforms to maximize impact.

1. Immediately upgrade all n8n instances to version 1.120.3 or later, where the vulnerability is patched. 2. Restrict administrative privileges to the minimum necessary number of users and enforce strong authentication mechanisms such as multi-factor authentication (MFA) for admin accounts. 3. Conduct an audit of all users with administrative access to ensure only trusted personnel have such privileges. 4. Monitor logs and system activity for unusual command execution or package installation attempts that could indicate exploitation attempts. 5. Implement network segmentation to isolate n8n hosts from critical infrastructure and sensitive data stores to limit potential lateral movement. 6. Review and harden the configuration of n8n workflows to minimize exposure of sensitive commands or scripts. 7. Educate administrators on the risks of command injection vulnerabilities and the importance of secure package management practices. 8. Consider deploying runtime application self-protection (RASP) or host-based intrusion detection systems (HIDS) to detect anomalous command execution. 9. Regularly update and patch all automation and workflow platforms as part of a robust vulnerability management program.