CVE-2026-21877 is a critical vulnerability affecting n8n, an open-source workflow automation platform. This vulnerability allows authenticated attackers to execute malicious code using the n8n service, potentially leading to full system compromise. The severity of this vulnerability is underscored by a CVSS score of 9.9, categorizing it as critical. Organizations utilizing affected versions must prioritize mitigation efforts to protect their systems effectively.
The vulnerability impacts all versions of n8n up to 0.121.2. The risk to organizations includes the possibility of unauthorized access, data loss, and integrity breaches. Given the potential for significant damage, organizations should act swiftly. It is recommended to upgrade to version 1.121.3, where this issue has been resolved.
While administrators can reduce exposure by disabling the Git node and limiting access for untrusted users, upgrading to the latest version is the most effective remediation strategy. Organizations are urged to address this vulnerability immediately to prevent exploitation.
The urgency for defenders cannot be overstated, as the conditions for exploitation are present. Organizations must ensure they are not using vulnerable versions of n8n and implement robust access controls to mitigate risks.
Vulnerability Details
n8n is an open-source workflow automation platform. In versions 0.121.2 and below, an authenticated attacker may be able to execute malicious code using the n8n service. This could result in full compromise and can impact both self-hosted and n8n Cloud instances. This issue is fixed in version 1.121.3.
The vulnerability is categorized under CWE-94: Improper Control of Generation of Code ('Code Injection') and CWE-434: Unrestricted Upload of File with Dangerous Type. The CVSS score of 9.9 indicates a critical severity level, reflecting the potential for high confidentiality, integrity, and availability impacts.
Technical Analysis
The root cause of this vulnerability arises from insufficient validation of user inputs when executing code through the n8n service. This flaw allows attackers to inject malicious scripts, which can lead to arbitrary code execution.
The attack vector is network-based, meaning that an attacker can exploit this vulnerability remotely. The attack complexity is classified as low, and only low privileges are required to execute the attack, significantly increasing its risk profile. User interaction is not necessary for exploitation, further complicating defense efforts.
The impacts of exploitation are severe, with high confidentiality, integrity, and availability impacts. Organizations must remain vigilant and employ measures to detect and respond to potential exploitation attempts.
Risk & Impact Analysis
The risk to organizations includes unauthorized access, data compromise, and operational disruptions. Given the nature of workflow automation platforms, a successful exploit could allow attackers to manipulate sensitive processes and data.
Organizations should understand the potential blast radius of this vulnerability. Since it can impact both self-hosted and cloud instances, the effects can be extensive, affecting multiple users and services within the organization.
The urgency assessment based on the CVSS score indicates that organizations should prioritize patching immediately. The absence of known exploits does not eliminate the need for prompt action, as the conditions for exploitation are present.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
This vulnerability affects all n8n versions prior to 1.121.3. Organizations should upgrade immediately to mitigate risks.
Mitigation & Remediation
To remediate this vulnerability, organizations must upgrade to n8n version 1.121.3, where the issue has been resolved. In addition, administrators can reduce exposure by disabling the Git node and limiting access for untrusted users until the upgrade can be performed.
For further security measures, organizations should consider implementing network controls and monitoring for abnormal behaviors that might indicate an attempt to exploit this vulnerability.
Continuous security testing can further validate the effectiveness of remediation efforts.
Detection Guidance
Organizations should monitor logs for indicators of unusual access patterns, particularly around the Git node functionality. Behavioral anomalies that deviate from normal operational patterns should be investigated promptly.
Network signatures that indicate unauthorized code execution attempts should be established, and system changes that coincide with n8n operations should be closely monitored.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2026-21877 lies in its demonstration of the critical need for robust input validation in workflow automation platforms.
This vulnerability represents a trend where attackers exploit insufficient validation to execute arbitrary code, stressing the importance of maintaining up-to-date software.
Security teams should take this incident as a lesson in the necessity of proactive vulnerability management, particularly in environments where automation is prevalent.
Organizations may benefit from establishing a vulnerability management program to enhance their security posture and reduce risks associated with similar vulnerabilities.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
.webp)