A flaw in Node.js Permission Model network enforcement leaves Unix Domain Socket (UDS) server operations without the required permission checks, while all comparable network paths correctly enforce them.

As a result, code running under --permission without --allow-net can create and expose local IPC endpoints, allowing communication with other processes on the same host outside of the intended network restriction boundary.

This vulnerability affects Node.js 25.x processes using the Permission Model where --allow-net is intentionally omitted to restrict network access. Note that --allow-net is currently an experimental feature.

NOTE: https://nodejs.org/en/blog/vulnerability/march-2026-security-releases#nodejs-permission-model-bypass-uds-server-bindlisten-works-without---allow-net-cve-2026-21711---medium