JUST IN: 🇺🇸 Head of US cyber defense agency CISA Madhu Gottumukkala uploaded sensitive documents into public ChatGPT, prompting a DHS investigation. pic.twitter.com/EHh7J94BRb — Remarks (@remarks) January 28, 2026The decision to use the public ChatGPT rather than an approved internal tool was central to the DHS investigation. Before his appointment to CISA, Gottumukkala served as South Dakota's Chief Information Officer and was later named Commissioner of the South Dakota Bureau of Information and Telecommunications. The CISA Chief Carelessly Used ChatGPT Who Is Madhu Gottumukkala? He also faced internal organisational conflict when attempting to remove CISA's Chief Information Officer, Robert Costello — a move that other political appointees reportedly blocked.