Yale New Haven Health data breach affects 5.5 million patients

Yale New Haven Health (YNHHS) is warning that threat actors stole the personal data of 5.5 million patients in a cyberattack earlier this month. YNHHS is a nonprofit healthcare network in Connecticut, the largest in the state, providing comprehensive care across five hospitals and 360 outpatient locations. It employs 30,000 health professionals and has an annual revenue of over $5.6 billion. On March 11, 2025, the organization first reported that it was dealing with a cybersecurity incident that occurred three days earlier. This incident caused IT system disruptions but did not impact patient care. Yale New Haven Health hired Mandiant to help with system restoration and forensic investigation while federal authorities were notified about the incident. On April 11, 2025, YNHHS informed the public that its investigation into the incident confirmed a data breach that may have exposed sensitive patient information to unauthorized actors. The stolen information varies by patient and in ... Read full article.