Harvard University data breach exposed info of 851,000 accounts

Hackers who breached Harvard University's Alumni Affairs and Development systems in November 2025 stole data linked to more than 850,000 unique email addresses, according to breach notification service Have I Been Pwned.

Harvard is a private Ivy League research university with over 20,000 faculty and staff, over 24,500 undergraduate and graduate students, and more than 400,000 alumni worldwide.

As the university discovered on November 18, 2025, the attackers gained access to the personal information of students, alumni, donors, staff, and faculty members, including email addresses, telephone numbers, home and business addresses, event attendance records, donation details, and "biographical information pertaining to University fundraising and alumni engagement activities."

However, Klara Jelinkova, Harvard's Vice President and University Chief Information Officer (CIO), said the breached IT systems didn't store Social Security numbers, passwords, payment card information, or financial information.