Bison State Bank Data Breach Exposes SSNs & Financial Account Information

Bison State Bank, a community-focused commercial bank based in Kansas and Missouri, recently experienced a data breach.

According to a disclosure filed with the Massachusetts Office of Consumer Affairs and Business Regulation, the breach was discovered after Bison State Bank detected suspicious activity in an employee's email account between April 17, 2025, and June 30, 2025. Upon investigation, it was determined that the account had been accessed by an unauthorized actor.

The compromised email account contained a range of personally identifiable information (PII), including full names, Social Security numbers, financial account details, driver’s license numbers and credit or debit card numbers.

The total number of impacted individuals across all states has not been specified, but the number of affected individuals in Massachusetts is reported as five.

Bison State Bank's response

Upon learning of the breach, Bison State Bank secured their network and launched a thorough investigation with the assistance of external cybersecurity professionals. They reviewed the potentially impacted data and, by Jan. 6, 2026, determined which individuals’ information was at risk.

To assist those affected, Bison State Bank is offering complimentary credit monitoring and identity theft protection services through IDX for up to twenty-four months. Impacted individuals will receive instructions and an enrollment code to activate these services, which include single-bureau credit monitoring and identity theft remediation support.

Those affected are encouraged to remain vigilant by reviewing financial account statements and credit reports regularly for signs of suspicious activity. Additional recommended steps include placing a fraud alert or security freeze on credit files and obtaining free annual credit reports from the three major credit bureaus.

The bank has also established a dedicated toll-free hotline at 833-788-9712 for questions related to the breach.