Full Report
A newly disclosed critical vulnerability, tracked as CVE-2026-25049, in the workflow automation platform n8n, allows authenticated users to execute arbitrary system commands on the underlying server by exploiting weaknesses in the platform’s expression evaluation mechanism. With a CVSS score of 9.4, the issue is classified as critical and poses a high risk to affected systems. The CVE-2026-25049 vulnerability is the result of insufficient input sanitization in n8n’s expression handling logic. Researchers found that the flaw effectively bypasses security controls introduced to mitigate CVE-2025-68613, an earlier critical vulnerability with a CVSS score of 9.9 that was patched in December 2025. Despite those fixes, additional exploitation paths remained undiscovered until now. Bypass of Previous Security Fixes for CVE-2026-25049 Vulnerability According to an advisory released Wednesday by n8n maintainers, the issue was uncovered during follow-up analysis after the earlier disclosure. The maintainers stated, “Additional exploits in the expression evaluation of n8n have been identified and patched following CVE-2025-68613.” They further warned that “an authenticated user with permission to create or modify workflows could abuse crafted expressions in workflow parameters to trigger unintended system command execution on the host running n8n.” The vulnerability is described as an “Expression Escape Vulnerability Leading to RCE,” reflecting its ability to break out of an n8n expression sandbox and reach the host operating system. The advisory was published under GitHub Security Advisory GHSA-6cqr-8cfr-67f8 and applies to the n8n package distributed via npm. Affected Versions and Mitigation Guidance The CVE-2026-25049 vulnerability affects all n8n versions earlier than 1.123.17 and 2.5.2. The issue has been fully patched in versions 1.123.17 and 2.5.2, and users are advised to upgrade immediately to these or later releases to remediate the risk. For organizations unable to upgrade right away, the advisory outlines temporary workarounds. These include restricting workflow creation and modification permissions to fully trusted users and deploying n8n in a hardened environment with limited operating system privileges and constrained network access. However, n8n’s maintainers emphasized that these measures do not fully resolve the vulnerability and should only be considered short-term mitigations. From a severity standpoint, n8n has adopted CVSS 4.0 as the primary scoring system for its advisories, while continuing to provide CVSS 3.1 vector strings for compatibility. Under CVSS 3.1, CVE-2026-25049 carries the vector AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H. The CVSS 4.0 metrics similarly rate the issue as critical, citing low attack complexity, network-based exploitation, low required privileges, and high impact to confidentiality, integrity, and availability. Researcher Insights and Potential Impact Although no specific Common Weakness Enumerations (CWEs) have been assigned, the real-world implications of exploiting this n8n vulnerability are severe. A successful attack could allow threat actors to compromise the server, steal credentials, exfiltrate sensitive data, and install persistent backdoors to maintain long-term access. The vulnerability was discovered with contributions from as many as ten security researchers. Those credited include Fatih Çelik, who also reported CVE-2025-68613, as well as Endor Labs’ Cris Staicu, Pillar Security’s Eilon Cohen, SecureLayer7’s Sandeep Kamble, and several independent researchers. In a technical deep dive covering both CVE-2025-68613 and CVE-2026-25049, Çelik stated that “they could be considered the same vulnerability, as the second one is just a bypass for the initial fix.” He explained that both issues allow attackers to escape the n8n expression sandbox mechanism and circumvent security checks designed to prevent command execution.
Analysis Summary