Provenance Isn't Proof: What to Check Before You `npm install -g` a Tunnel CLI
Two things are true in November 2026. npm 12 now refuses to run dependency install scripts by default, which closes the most common supply-chain delivery path. And in the same year, attackers have shipped malicious npm releases that carried valid provenance attestations, plus payloads that never touch an install script at all. If you are about to run npm install -g on a tunnel client, both facts matter. A tunnel CLI is a long-lived process that holds an auth token, inherits your shell's environment variables and relays traffic between the public internet and your localhost. This guide covers what npm 12 changes, what provenance does and does not prove, and a pre-install checklist: version pinning, ignore-scripts , checksum-verified standalone binaries and egress allowlists. Why a tunnel client is a high-value target A tunnel client runs for hours or days, with your user's privileges, on the machine where your code, keys and .env files live, and on a network path where a t...
