GitHub Breach 2026 Explained: How Hackers Stole 3,800 Internal Repositories Through a Supply Chain Attack

The 2026 GitHub breach exposed nearly 3,800 internal repositories through a sophisticated software supply chain attack involving poisoned npm packages, stolen developer tokens, and a malicious VS Code extension update. This article explains how TeamPCP infiltrated trusted developer ecosystems, compromised GitHub infrastructure, and revealed critical weaknesses in modern open-source security, CI/CD pipelines, and software dependency management worldwide.