Proxy authentication in Snyk CLI for Windows allows developers to authenticate local network traffic through a centralized proxy, ensuring only authenticated users can access the public internet. This feature supports SPNEGO-based Kerberos and NTLM protocols, enabling secure DevSecOps workflows within enterprise environments subject to stringent audit and compliance regulations. The Snyk CLI now supports proxy authentication by default as of v1.1008.0, making it easier for developers to run scans from their development environments before releasing code changes.