Cybersecurity researchers have detailed two critical vulnerabilities discovered in the n8n workflow automation platform, which could allow attackers to execute arbitrary commands on affected systems. These flaws, now patched, pose a significant risk to sensitive data and system integrity for users of the popular open-source tool. The vulnerabilities were reported by Pillar Security and have been assigned CVSS scores of 9.4 and 9.5, highlighting their severity.
The security issues primarily revolve around expression evaluation and sandbox escapes within the n8n platform. Successful exploitation could grant attackers unauthorized access to execute system commands, potentially leading to remote code execution (RCE) and the decryption of sensitive credentials. All n8n deployments, both self-hosted and cloud-based, are impacted by these vulnerabilities, emphasizing the need for immediate updates.
Critical Vulnerabilities Found in n8n Workflow Automation
Two severe security flaws have been identified and subsequently patched in the n8n workflow automation platform. Pillar Security researchers unearthed these vulnerabilities, which could enable attackers to achieve arbitrary command execution. The most critical of these, tracked as CVE-2026-27577, involves an expression sandbox escape with a CVSS score of 9.4. This vulnerability allows authenticated users to execute arbitrary code on the host running n8n by crafting specific expressions within workflow parameters.
According to Pillar Security, CVE-2026-27577 is a flaw within the expression compiler. A missing case in the Abstract Syntax Tree (AST) rewriter allows malicious processes to bypass intended transformations, granting any authenticated expression the ability to perform remote code execution. This means an attacker with legitimate access to create or modify workflows could leverage this to gain full control over the n8n host.
Unauthenticated Expression Evaluation and Command Execution
A second critical vulnerability, CVE-2026-27493, carries a CVSS score of 9.5 and allows for unauthenticated expression evaluation through n8n’s Form nodes. This vulnerability, described as a “double-evaluation bug,” can be exploited through public-facing form endpoints which do not require authentication. By simply inputting a crafted payload into fields such as the “Name” field of a public “Contact Us” form, an attacker could execute arbitrary shell commands on the n8n server.
The implications of chaining CVE-2026-27493 with an expression sandbox escape like CVE-2026-27577 are particularly concerning. When combined, these vulnerabilities can escalate to full remote code execution on the n8n host. Furthermore, Pillar Security noted that attackers could exploit these flaws to access and read the N8N_ENCRYPTION_KEY environment variable. This key is crucial for decrypting all sensitive credentials stored within n8n’s database, including AWS keys, database passwords, OAuth tokens, and API keys.
Additional Vulnerabilities and Mitigation Strategies
Beyond the two critical RCE vulnerabilities, n8n versions 2.10.1, 2.9.3, and 1.123.22 also address two other significant flaws. CVE-2026-27495 (CVSS 9.4) is a code injection vulnerability within the JavaScript Task Runner sandbox, allowing authenticated users to execute arbitrary code outside the sandbox. Similarly, CVE-2026-27497 (CVSS 9.4) enables authenticated users to leverage the Merge node’s SQL query mode to execute arbitrary code and write files on the n8n server.
To mitigate these risks, n8n recommends immediate patching to the latest versions. For users unable to patch immediately, several workarounds are suggested. For CVE-2026-27577, it is advised to restrict workflow creation and editing permissions to trusted users and deploy n8n in a hardened environment with limited operating system privileges and network access. For CVE-2026-27493, users can review form node usage, or disable the Form node and Form Trigger node by adding `n8n-nodes-base.form` and `n8n-nodes-base.formTrigger` respectively to the NODES_EXCLUDE environment variable.
Additional mitigation strategies include using external runner mode (N8N_RUNNERS_MODE=external) for CVE-2026-27495 to limit the blast radius. For CVE-2026-27497, disabling the Merge node by adding `n8n-nodes-base.merge` to the NODES_EXCLUDE environment variable is recommended. While these workarounds can offer short-term protection, n8n’s maintainers caution that they do not fully remediate the underlying risks. The company has not reported any active exploitation of these vulnerabilities in the wild, but users are strongly encouraged to update their installations to the latest secure versions to ensure optimal protection against potential threats.