n8n was letting outside data cross the line from input to action. That means a self-hosted automation server can become the place where code runs, files get written, or fake triggers are accepted as real, which is a bigger failure than a single broken node.
NCSC says multiple high-severity flaws were fixed in 2.10.1, 2.9.3, 1.123.22 and related releases. The advisory spans Form nodes, the Python Code node, the JavaScript Task Runner sandbox, Merge, Read/Write Files from Disk, workflow expression evaluation, core workflow editing, GitHub Webhook Trigger, ZendeskTrigger, Guardrail, and Chat Trigger, with issues including code injection, eval injection, improper authentication, authorization bypass, and missing webhook signature checks.
For teams self-hosting n8n, the risk is not limited to one feature or one CVE. If the platform handles sensitive credentials or production integrations, an unpatched instance can expose the automation plane and the systems it controls, even when the original workflow looks harmless.