GitHub announced on 20 October 2026 (changelog rewritten for clarity on 21 October) a package firewall that sits between endpoints or internal registries and the upstream package repositories and, GitHub says, "inspects both metadata requests and package downloads for signs of malicious activity, acting as an install-time policy gate."

GitHub says it is responding to a recent flood of malware attacks that exploit systems at package installation time, and that agents and CI runners are particularly vulnerable because they install dependencies without a human in the loop.

Administrators set enterprise policy controls; GitHub says those available today include a configurable cooldown period, checks against the GitHub Advisory Database for malware or vulnerability advisories, and supply-chain checks such as attestation downgrades. Coding agents and CI/CD hosts then send their requests through the firewall instead of directly to the upstream registries, and users can request an exception if a package is blocked in error.

GitHub says the firewall currently supports only npm packages, is available in public preview to GitHub Enterprise Cloud customers (including GitHub Enterprise Cloud with data residency), is free during the preview and will be charged on metered usage, similar to Actions billing, at general availability.

GitHub's documentation says the cooldown minimum age can be set between 1 and 365 days, or 0 to disable it, with a default of 1 day, and that the vulnerability-advisory control defaults to blocking Critical only. (source: GitHub)