U.S. infrastructure contractor MasTec, Inc. disclosed a breach affecting 25,220 individuals after suspicious activity in a third-party solution was investigated from October 2025 through February 2026. Notification letters went out June 5, 2026.
What was exposed
- Names, dates of birth, and addresses
- Social Security numbers
- Financial account details and some account credentials
Action items
- Freeze or monitor credit if you received a MasTec notice.
- Rotate passwords on any work or vendor portals tied to MasTec projects.
- Report suspicious payroll or benefits verification calls citing real SSN fragments.
Canonical record: MasTec 2025 third-party breach on BreachHistory.
Sources: Maine AG, ClassAction.org