Privacy Unpacked

Weekly breach brief

Data breaches in the week of 29 Dec – 4 Jan 2026

30 data breaches on the tracker, 30 confirmed by the organisation or a regulator.

Breaches
30
Notices in CA and WA
16
Ransomware claims
101
Largest
320,973

The largest

  1. Monroe University 320,973 people United States
  2. Cyrus D. Mehta & Partners PLLC 8,845 people United States
  3. Informa et al 5,959 people United States
  4. Chesapeake Bay Maritime Museum Inc 5,181 people United States
  5. Gregory A Burrell Chapter 13 Trustee 4,082 people United States
  6. Cerenade 1,663 people United States

Every breach this week, by country

United States 30

Ransomware claims

Gangs named 101 organisations on their leak sites this week, against 207 the week before. A claim is the gang’s word, not a confirmed breach.

Every week

Follow the brief: one entry a week (Atom). The 2026 report has the year so far.

From the data breach tracker: official notices, breach databases and the news, every fact with its source. Open data (CC BY 4.0) · How the tracker works · Official registers · Corrections and changes · Found a mistake? Tell us and we correct it.