CVE-2026-27495

n8n is an open source workflow automation platform. Prior to versions 2.10.1, 2.9.3, and 1.123.22, an authenticated user with permission to create or modify workflows could exploit a vulnerability in the JavaScript Task Runner sandbox to execute arbitrary code outside the sandbox boundary. On instances using internal Task Runners (default runner mode), this could result in full compromise of the n8n host. On instances using external Task Runners, the attacker might gain access to or impact other task executed on the Task Runner. Task Runners must be enabled using `N8N_RUNNERS_ENABLED=true`. The issue has been fixed in n8n versions 2.10.1, 2.9.3, and 1.123.22. Users should upgrade to one of these versions or later to remediate the vulnerability. If upgrading is not immediately possible, administrators should consider the following temporary mitigations. Limit workflow creation and editing permissions to fully trusted users only, and/or use external runner mode (`N8N_RUNNERS_MODE=external`) to limit the blast radius. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

An attacker with a low-privileged n8n account — obtained via credential stuffing, phishing a developer, or compromising a service account used by CI/CD — navigates to the workflow editor. They create or modify a workflow containing a JavaScript Code node and craft a payload exploiting CWE-94 in the Task Runner sandbox to execute arbitrary OS commands. With internal runner mode (default), this immediately yields RCE on the n8n host. The attacker then dumps the n8n environment variables and database, extracting API keys for OpenAI/Anthropic, database connection strings, OAuth tokens, and webhook secrets stored as workflow credentials. They establish persistence via a reverse shell, then pivot laterally through the internal network using n8n's pre-authorized connections to internal APIs, cloud storage, and databases — effectively inheriting all trust relationships the automation platform held. The attack is particularly dangerous in AI-heavy environments where n8n orchestrates LLM calls, RAG pipelines, and multi-agent workflows, as full compromise of the orchestration layer means full visibility and control over the entire AI automation stack.