External risk intelligence

n8n Workflow Automation Command Execution Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.4)

CVE-2026-27577

n8n is a workflow automation platform that is frequently deployed as a network-accessible service to facilitate integrations. While it is often hosted in internal or controlled environments, it is commonly web-accessible to perform its function, making reachable internet exposure plausible depending on the specific deployment configuration.

Code Injection

N8n

before 1.123.222.0.0 to before 2.9.32.10.0 to before 2.10.1

Halo Surface Signal: 3 out of 5 — possibly public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This advisory concerns vulnerabilities in the n8n workflow automation platform that could allow an authenticated user to execute unintended system commands. The issue arises from how the platform handles crafted expressions within workflow parameters. While fixes are available, organizations should confirm their exposure and consider access controls as a temporary measure if immediate upgrades are not feasible.

Unauthenticated users can trigger system commands.
Essential for understanding workflow automation risks.
Confirm relevance and review access controls.

Attack Path

How an attacker could exploit the issue

An attacker can start by gaining access to an n8n instance, requiring authenticated user privileges to create or modify workflows. They can then craft specific expressions within workflow parameters to manipulate the system. This can lead to unintended command execution on the server hosting n8n, allowing the attacker to gain significant control.

Authenticated user with edit permissions required.
Crafting expressions in workflow parameters.
Unintended system command execution.

Live Threat

Current exploitation, exposure, and threat context

An authenticated user with workflow modification permissions could trigger unintended system command execution on the host running n8n by crafting malicious expressions in workflow parameters. This could impact the integrity and availability of the host system when supported by the advisory's conditions.

Host system commands and data.
Abusing crafted expressions in workflows.
Unintended system command execution.

Operational Fix

Recommended remediation, mitigation, and detection steps

Ownership of this vulnerability likely falls to the platform or application teams responsible for the n8n deployment, in coordination with security teams for exposure assessment. The first practical step is to identify all n8n instances, determine their reachability and criticality, and then assign an accountable owner for remediation.

Platform or application teams own remediation.
Verify reachability and business criticality.
Plan upgrade or implement mitigations.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is the n8n platform used for?

n8n is an open-source workflow automation tool that lets users connect various services and apps to create complex, automated data flows. Because it often sits between different systems to move data or trigger actions, it is frequently set up as a network-accessible service to integrate with web-based APIs and platforms.

What does CWE-94 mean in the context of CVE-2026-27577?

CWE-94 refers to improper control of generation of code, or code injection. In this specific vulnerability, the n8n expression evaluation engine does not properly sanitize input. This allows an attacker to insert malicious code into a workflow parameter, which the server then executes as a system command.

How is this vulnerability triggered?

An attacker must already have access to an n8n account with permissions to create or edit workflows. They trigger the bug by saving a specially crafted expression within those parameters. Simply visiting the login page or having read-only access does not trigger the flaw; it requires the ability to define how a workflow behaves.

Why should I care if my n8n instance is network-accessible?

Halo Surface Signal notes that n8n is often deployed as a web-accessible service, which increases the likelihood of external reachability. If your instance is exposed to the internet, any compromised or malicious account with workflow-editing privileges could potentially gain control over the host system itself.

Is upgrading the only way to fix this?

Upgrading to n8n versions 2.10.1, 2.9.3, 1.123.22, or later is the only full remediation. If you cannot update immediately, limit workflow-editing permissions to only the most trusted users and ensure the n8n instance is running in a hardened environment with strictly limited operating system privileges and network access.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.