Cornerstone Behavioral Healthcare Data Breach History

This page tracks the Cornerstone Behavioral Healthcare data breach history and cybersecurity incidents affecting Cornerstone Behavioral Healthcare (United States). BreachHistory currently indexes 1 publicly disclosed or catalogued incident spanning 2026, with approximately 15 thousand records reported as exposed across all indexed events. These totals may include overlapping datasets or third-party estimates and should not be interpreted as unique affected users.

The Cornerstone Behavioral Healthcare breach timeline includes major data breaches, cyber attacks, data leaks, credential exposures, API abuse, and other security incidents. Each incident provides details on the estimated records exposed, attack method, affected data types, and supporting public sources. Currently, 0 incidents are company-confirmed.

Largest Cornerstone Behavioral Healthcare Data Breaches

The largest indexed incidents include the 2026 Cornerstone Behavioral Healthcare — May 26 ransomware; 14,830 patients (HHS);…. Record counts originating from threat actors or leak sites should be treated as estimates unless confirmed by Cornerstone Behavioral Healthcare or a regulator. Below is the list of large data breaches:

• 2026 2026 Cornerstone Behavioral Healthcare — May 26 ransomware; 14,830 patients (HHS); SUD/SSNs — about 14.8K records exposed · Catalogued incident

What Information Was Exposed?

Depending on the incident, exposed data may include Social Security numbers and national IDs, names, physical addresses, health and medical (PHI) records, dates of birth, and other personal information (PII). The exact data varies between incidents, so review each breach page before assuming your information was affected.

Cornerstone Behavioral Healthcare Data Breach 2026

At the time of this update, BreachHistory catalogues 1 2026 incident related to Cornerstone Behavioral Healthcare. Most recent entry: 2026 Cornerstone Behavioral Healthcare — May 26 ransomware; 14,830 patients (HHS); SUD/SSNs. New incidents are added as official disclosures, regulatory filings, or credible cybersecurity reports become available.

What To Do If You Were Affected

If you believe your account may have been involved in a Cornerstone Behavioral Healthcare data breach, change any reused passwords, enable multi-factor authentication (MFA), monitor your account for suspicious activity, and be cautious of phishing emails or fake breach notifications.

This Cornerstone Behavioral Healthcare breach history is maintained by BreachHistory using public disclosures, regulatory filings, security research, and clearly labelled third-party claims. For the complete breach timeline, records exposed, incident details, and AI Breach Risk Score, explore the sections on this page.