Onset Data Breach Exposes Sensitive Personal Information Onset recently disclosed a potential security incident to the Massachusetts Attorney General, revealing that sensitive personal identifiable information (PII) under its protection may have been compromised. The breach notice, filed without details on the nature of the attack, indicates that exposed data could include names, Social Security numbers, financial account information, driver’s license details, and credit/debit card numbers—though the exact impact varies by individual. On December 12, 2025, Onset began notifying affected individuals via mail, providing them with specifics on the compromised data and offering 24 months of complimentary credit monitoring services. The breach notice submitted to Massachusetts authorities is available for review. The full scope of the incident and its root cause remain undisclosed.