CVE-2026-21893 Overview
A command injection vulnerability has been identified in n8n, an open source workflow automation platform. This vulnerability exists in n8n's community package installation functionality, allowing authenticated users with administrative permissions to execute arbitrary system commands on the n8n host under specific conditions. The vulnerability affects versions from 0.187.0 to before 1.120.3.
Critical Impact
Authenticated administrators can achieve full system command execution on the underlying host, potentially leading to complete infrastructure compromise, data exfiltration, and lateral movement within the network.
Affected Products
- n8n versions 0.187.0 through 1.120.2
- Self-hosted n8n deployments with community package installation enabled
- Docker and Kubernetes-based n8n installations running vulnerable versions
Discovery Timeline
- 2026-02-04 - CVE CVE-2026-21893 published to NVD
- 2026-02-05 - Last updated in NVD database
Technical Details for CVE-2026-21893
Vulnerability Analysis
This command injection vulnerability (CWE-20: Improper Input Validation) exists in n8n's community package installation functionality. The platform allows administrators to install community-contributed nodes and packages to extend workflow capabilities. However, the input handling mechanism for package names or installation parameters fails to properly sanitize user-controlled data before passing it to system shell commands.
When an authenticated administrator attempts to install a community package, the vulnerability allows specially crafted input to break out of the intended command context and execute arbitrary system commands. This exploitation requires administrative privileges but can result in complete compromise of the underlying host system where n8n is deployed.
Root Cause
The root cause is improper input validation (CWE-20) in the community package installation handler. User-supplied input is not adequately sanitized before being incorporated into shell commands, allowing command separator characters and shell metacharacters to be interpreted by the underlying operating system. This represents a classic command injection pattern where trusted input boundaries are not enforced.
Attack Vector
The attack is network-based and requires the attacker to have authenticated administrative access to the n8n instance. Once authenticated, the attacker can leverage the community package installation feature to inject malicious commands. The attack flow typically involves:
- Authenticating to n8n with administrative credentials
- Navigating to the community package installation interface
- Crafting a malicious package name or parameter containing shell metacharacters
- Submitting the installation request to trigger command execution
- Achieving arbitrary command execution on the host system
The vulnerability exploitation mechanism involves injecting shell metacharacters into package installation parameters. For detailed technical analysis, refer to the GitHub Security Advisory.
Detection Methods for CVE-2026-21893
Indicators of Compromise
- Unusual process spawning from n8n service processes (e.g., shells, system utilities)
- Unexpected network connections originating from the n8n host
- Anomalous entries in community package installation logs containing shell metacharacters
- Signs of privilege escalation or lateral movement from the n8n server
Detection Strategies
- Monitor system call activity from n8n processes for unauthorized command execution
- Implement application-layer logging to capture all community package installation requests
- Deploy file integrity monitoring on critical n8n directories and configuration files
- Configure SIEM rules to alert on unusual process trees spawned by n8n services
Monitoring Recommendations
- Enable verbose logging for n8n community package operations
- Establish baseline behavior for n8n process activity and alert on deviations
- Monitor for outbound connections from the n8n server to unknown destinations
- Review authentication logs for suspicious administrative access patterns
How to Mitigate CVE-2026-21893
Immediate Actions Required
- Upgrade n8n to version 1.120.3 or later immediately
- Audit administrative user accounts and remove unnecessary privileges
- Review recent community package installation logs for suspicious activity
- Restrict network access to n8n administrative interfaces to trusted IP ranges
Patch Information
n8n has released version 1.120.3 which addresses this command injection vulnerability. The fix is available in the GitHub commit. Organizations should prioritize upgrading all n8n instances to this patched version. For detailed remediation guidance, consult the GitHub Security Advisory.
Workarounds
- Disable community package installation functionality until patching is complete
- Implement strict network segmentation to isolate n8n deployments from critical infrastructure
- Enforce multi-factor authentication for all administrative accounts
- Deploy web application firewalls to filter potentially malicious installation requests
# Configuration example - Disable community packages in environment
export N8N_COMMUNITY_PACKAGES_ENABLED=false
# Restart n8n service to apply changes
systemctl restart n8n
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
