Columbia University

Disclosed Aug 7, 20253,067,242 affectedConfirmed

Hacker steals data of 868,969 Columbia students, applicants and staff

Columbia University told Maine's attorney general that a hacker who breached its network in May 2025, discovered after a June 24 outage, stole data on 868,969 people including names, birth dates, SSNs, contact details, academic history and financial aid and health information.

What is known

People affected	3,067,242 (as reported by the organization)
Disclosed	Aug 7, 2025
Discovered	Jul 8, 2025
Happened	May 16, 2025
Attack	Hacking
Data exposed	NamesHealthInsuranceCredentials and tokensDates of birthSocial Security numbersAddressesPhone numbersEducation recordsFinancialOtherGovernment IDsPayment cards
Sector	Education · US
Status	Confirmed

Sources

Official noticeoag.ca.gov

California Attorney General breach notice: Columbia University

Official noticeatg.wa.gov

Washington Attorney General breach notice: Columbia University

Official noticeattorneygeneral.delaware.gov

Notice letter filed with the Delaware DOJ: Columbia University

Official noticejustice.oregon.gov

Oregon DOJ breach notice: Columbia University

Newsbleepingcomputer.com

Columbia University data breach impacts nearly 870,000 individuals

Official noticeoag.my.site.com

Texas Attorney General data security breach report BR-0005050: Columbia University

Official noticeago.vermont.gov

Vermont Attorney General: 2025-08-07 Columbia University Data Breach Notice to Consumers

Official noticein.gov

Indiana Attorney General 2025 data breach report: Columbia University

Notices filed

Residents of CAAug 7, 2025

California AGCount not stated

Residents of WAAug 7, 2025

Washington AG54,075 people

Residents of DEAug 7, 2025

Delaware DOJ1,818 people

Residents of ORAug 7, 2025

Oregon DOJ868,969 people

TotalAug 7, 2025

Research868,969 people

Residents of VTAug 7, 2025

Vermont AGCount not stated

Residents of INAug 7, 2025

Indiana AG4,078 people

Residents of TXMay 20

Texas AG161,544 people

History of this record

source2026-09-25

empty to https://www.in.gov/attorneygeneral/consumer-protection-division/id-theft-prevention/files/DB-Year-to-Date-Report-2025.pdfby backfillSource

source2026-09-25

empty to https://ago.vermont.gov/document/2025-08-07-columbia-university-data-breach-notice-consumersby backfillSource

data_types2026-09-25

["names","health","insurance","credentials","dob","ssn","addresses","phone","education","financial","other"] to ["names","health","insurance","credentials","dob","ssn","addresses","phone","education","financial","other","government-id","payment-card"]by backfillSource

records2026-09-25

868969 to 3067242by backfillSource

data_types2026-09-25

["names","health","insurance","credentials"] to ["names","health","insurance","credentials","dob","ssn","addresses","phone","education","financial","other"]by seedSource

summary2026-09-25

empty to Columbia University told Maine's attorney general that a hacker who breached its network in May 2025, discovered after a June 24 outage, stole data on 868,969 people including names, birth dates, SSNs, contact details, academic history and by seedSource

title2026-09-25

empty to Hacker steals data of 868,969 Columbia students, applicants and staffby seedSource

data_types2026-09-25

[] to ["names","health","insurance","credentials"]by backfillSource

records_basis2026-09-25

empty to organizationby backfillSource

records2026-09-25

empty to 868969by backfillSource

attack2026-09-25

unknown to hackingby backfillSource

discovered2026-09-25

empty to 2025-07-08by backfillSource

Added2026-09-25

First recordedby backfillSource

First seen 2026-09-25 (California AG), confirmed by California AG. Record counts are as reported. Not legal advice.

Everything about Columbia University