Understanding the Critical Vulnerability CVE-2026-25049 in n8n

The workflow automation platform n8n has recently come under scrutiny due to a critical vulnerability disclosed as CVE-2026-25049. This exploit compromises the security of authenticated users, allowing them to execute arbitrary system commands on the hosting server. With a raw assessment score of 9.4 on the Common Vulnerability Scoring System (CVSS), this issue poses significant risks to affected systems.

Nature of the Vulnerability

Expression Escape Vulnerability

CVE-2026-25049 arises from inadequate input sanitization within n8n’s expression evaluation mechanism. The vulnerability reveals that previously implemented security measures designed to mitigate the earlier CVE-2025-68613 were insufficient. Despite being patched in December 2025, new avenues for exploitation have emerged, requiring further rectification.

Implications for Authenticated Users

This vulnerability enables any authenticated user with permissions to create or modify workflows to exploit crafted expressions in workflow parameters. As stated in the advisory from n8n’s maintainers, doing so can lead to unintended command execution on the host operating system. This effectively allows for a security breach that could compromise the server’s integrity.

Bypassing Previous Fixes

The identification of CVE-2026-25049 reflects a critical examination of n8n’s security posture following vulnerabilities disclosed earlier. The maintainers highlighted that “additional exploits in the expression evaluation of n8n have been identified and patched” since the last major vulnerability report. This emphasizes the need for ongoing vigilance in securing applications and addressing potential weak points.

Critical Advisory

The vulnerability is categorized as an “Expression Escape Vulnerability Leading to Remote Code Execution (RCE),” showcasing its ability to escape the n8n expression sandbox and potentially access the host’s operating system. The advisory aligns with GitHub Security Advisory GHSA-6cqr-8cfr-67f8, ensuring transparency and consumer awareness.

Affected Versions and Remediation

Versions at Risk

CVE-2026-25049 affects all n8n versions released before 1.123.17 and 2.5.2. It is crucial for users to upgrade to these versions—1.123.17 and 2.5.2—or any subsequent releases as these contain the necessary patches to address this vulnerability.

Recommended Mitigation Steps

For organizations unable to implement an immediate upgrade, there are temporary workarounds. These include:

• Restricting Permissions: Limit workflow creation and modification permissions to trusted users only.
• Hardened Environment: Deploy n8n within a secured environment, limiting operating system privileges and network access.

While these approaches offer short-term relief, they do not fully resolve the vulnerability. Organizations should prioritize upgrading their installations.

Severity Assessment Through CVSS

n8n employs CVSS 4.0 as its primary vulnerability scoring system while maintaining compatibility with CVSS 3.1 metrics. Under CVSS 3.1, CVE-2026-25049 is rated as high severity, with metrics indicating low attack complexity and high potential impact on confidentiality, integrity, and availability.

The severity and risk factors necessitate immediate attention, as the CVSS 4.0 metrics consistently reflect this vulnerability’s critical nature.

Insights from Security Researchers

Research efforts credited to multiple security experts underscore the gravity of CVE-2026-25049. The contributions of skilled individuals, including Fatih Çelik and professionals from various security firms, highlight collaborative efforts in identifying and addressing this vulnerability.

The Nature of Exploits

According to Fatih Çelik, the vulnerabilities CVE-2025-68613 and CVE-2026-25049 could be viewed as interconnected, with the latter acting as a bypass for initial fixes. Both vulnerabilities exploit the n8n expression sandbox mechanism, allowing attackers to circumvent security measures intended to mitigate command execution.

In summary, the criticality of CVE-2026-25049 underscores the importance of rigorous security practices. Continuous monitoring, timely updates, and collaborative efforts in the cybersecurity community are key to safeguarding against such vulnerabilities.