BOK Financial reported a data breach involving its third-party service provider, Linedata Services Inc., which experienced a cybersecurity incident on August 11, 2025. The breach was detected when an unauthorized third party potentially accessed sensitive personal information stored in Linedata’s systems. BOK Financial initiated an investigation upon notification (August 12, 2025) and confirmed that exposed data may include names and Social Security numbers of affected individuals. By November 21, 2025, BOK Financial began notifying impacted individuals via mail, offering 12 months of complimentary credit monitoring as a remedial measure. The breach notice, filed with the Maine Attorney General, indicated that the compromised data varied per individual but included highly sensitive personally identifiable information (PII). The incident highlights risks associated with third-party vendor vulnerabilities and the potential for large-scale exposure of customer data, though the full scope of misuse (e.g., fraud or identity theft) remains undetermined as of the notification.