People search MasTec data breach timeline because the brand sits on billions of accounts, credentials, and cloud workloads. BreachHistory indexes 1 MasTec-linked incident, with headline counts up to 25K+ in catalog rows. This page maps every attested event through 2026 with internal links to canonical records.
Why MasTec breach history matters
MasTec operates in Construction (United States). Across indexed rows, recurring themes include cloud and database misconfiguration, third-party and supply-chain exposure, zero-day exploitation and malware. Understanding the chronological pattern helps security teams, customers, and regulators separate confirmed disclosures from forum marketing.
Full timeline through 2026
2025 — third-party zero-day breach exposed 25,220 people (June 2026 notices)
Cataloged incident. MasTec, Inc., a U.S. infrastructure construction company, reported to the Maine Attorney General that 25,220 individuals were affected by unauthorized network access tied to a zero-day vulnerability in one of its third-party solutions. The company was notified of suspicious activity affecting the vendor solution in October 2025; forensic review concluded in February 2026 that names, dates of birth, addresses, Social Security numbers, financial account details, and some account credentials were compromised. Consumer Exposed categories include Names, dates of birth, addresses, Social Security numbers, financial account details, and some account credentials. BreachHistory cites approximately 25K+ affected records in this row. See the mastec-third-party-zero-day2025 and canonical BreachHistory entry.
Patterns and analysis
- Cloud and database misconfiguration — appears across multiple MasTec catalog entries; prioritize controls that address this class of failure.
- Third-party and supply-chain exposure — appears across multiple MasTec catalog entries; prioritize controls that address this class of failure.
- Zero-day exploitation and malware — appears across multiple MasTec catalog entries; prioritize controls that address this class of failure.
- Record-count hygiene — BreachHistory indexes actor-cited figures separately from company-confirmed totals; read each row's technicalWriteup before treating counts as fact.
- 2026 monitoring — New disclosures roll into this timeline as they are verified or labeled unverified per catalog policy.
What to do if you may be affected
- Step 1: Enable phishing-resistant MFA on every account tied to this brand.
- Step 2: Use unique passwords and a password manager—breach rows often involve credential reuse.
- Step 3: Monitor official company breach notices and regulator filings, not dark-web downloads.
- Step 4: Bookmark the MasTec company page for new 2026+ disclosures.
Canonical BreachHistory hub
Explore every indexed row: breachhistory.com/mastec · Latest: mastec-third-party-zero-day2025.
Sources: BreachHistory catalog (1 row for MasTec), company and regulator disclosures cited in individual breach records.