Cullen/Frost Bankers Data Breach Exposes Sensitive Information of Nearly 4,700 Individuals
Cullen/Frost Bankers, Inc., a Texas-based financial holding company and parent of Frost Bank, recently disclosed a data breach affecting 4,698 individuals in the U.S. The incident was reported to the U.S. Department of Health and Human Services on March 26, 2026, though the company has not publicly revealed the cause or specifics of the breach.
Founded in 1868 and headquartered in San Antonio, Cullen/Frost Bankers provides commercial and consumer banking, international banking, and wealth management services. Current and former clients of the bank may have had sensitive personally identifiable information (PII) compromised in the incident.
Class action law firm Shamis & Gentile P.A. is investigating the breach and potential legal claims for affected individuals. Those impacted may be eligible for compensation as part of ongoing legal efforts.
Source: https://www.claimdepot.com/investigations/frost-bank-data-breach-2026
Frost cybersecurity rating report: https://www.rankiteo.com/company/frostbank
"id": "FRO1778783685",
"linkid": "frostbank",
"type": "Breach",
"date": "3/2026",
"severity": "85",
"impact": "4",
"explanation": "Attack with significant impact with customers data leaks"{'affected_entities': [{'customers_affected': '4698',
'industry': 'Banking, Wealth Management',
'location': 'San Antonio, Texas, U.S.',
'name': 'Cullen/Frost Bankers, Inc.',
'type': 'Financial Holding Company'}],
'data_breach': {'number_of_records_exposed': '4698',
'personally_identifiable_information': 'Yes',
'sensitivity_of_data': 'High',
'type_of_data_compromised': 'Personally Identifiable '
'Information (PII)'},
'date_publicly_disclosed': '2026-03-26',
'description': 'Cullen/Frost Bankers, Inc., a Texas-based financial holding '
'company and parent of Frost Bank, recently disclosed a data '
'breach affecting 4,698 individuals in the U.S. The incident '
'involved the compromise of sensitive personally identifiable '
'information (PII) of current and former clients.',
'impact': {'data_compromised': 'Sensitive personally identifiable information '
'(PII)',
'identity_theft_risk': 'High',
'legal_liabilities': 'Potential legal claims and compensation for '
'affected individuals'},
'investigation_status': 'Ongoing',
'references': [{'source': 'U.S. Department of Health and Human Services'},
{'source': 'Shamis & Gentile P.A.'}],
'regulatory_compliance': {'legal_actions': 'Class action investigation by '
'Shamis & Gentile P.A.',
'regulatory_notifications': 'Reported to the U.S. '
'Department of Health '
'and Human Services'},
'title': 'Cullen/Frost Bankers Data Breach Exposes Sensitive Information of '
'Nearly 4,700 Individuals',
'type': 'Data Breach'}