GitHub Internal Repositories Breached: Source Code and Internal Data Allegedly Exfiltrated in 2026 Supply Chain Attack
In a significant security incident unfolding on May 20, 2026, GitHub confirmed unauthorized access to its internal repositories. The breach involved the exfiltration of sensitive internal source code and organizational data, reportedly totaling around 3,800 to 4,000 private repositories. A threat actor surfaced on underground forums advertising the stolen materials for sale, complete with directory listings of compressed archives and sample verification offers.