Cornerstone First Mortgage Discloses 2023 Data Breach Affecting 73 Massachusetts Residents On March 5, 2026, San Diego-based mortgage lender Cornerstone First Mortgage reported a data breach impacting at least 73 Massachusetts residents who provided personal information to the company or its predecessor, Cornerstone First Mortgage Inc. The incident exposed Social Security numbers and other sensitive data. The breach occurred between July and August 2023 but was not discovered until September 2025, leaving a prolonged window of potential exposure. The company has not disclosed the cause of the breach or identified the responsible party. In response, Cornerstone First Mortgage is offering 24 months of complimentary credit monitoring and identity protection services through Kroll, including single-bureau credit monitoring, fraud consultation, and identity theft restoration. Affected individuals must enroll by May 11, 2026, using activation codes provided directly by the company. The breach was reported to the Massachusetts Office of Consumer Affairs and Business Regulation, and the company has advised impacted customers to monitor financial accounts, review credit reports, and consider placing fraud alerts or security freezes on their credit files.