The Oncology Institute reported a cybersecurity incident involving unauthorized access to information systems managed by a third-party vendor, likely TriZetto Provider Solutions. This breach affects patient data across multiple healthcare organizations. The third-party administrator, Kroll, notified the Oncology Institute of the breach in May 2026. The incident was initially disclosed in late 2025, with ongoing investigations. The breach has impacted millions of individuals, but no detailed technical vulnerability or exploitation method has been publicly identified. No ransomware group has claimed responsibility, and the vendor has not been named officially. The vendor has established a patient portal for affected individuals to obtain information.

Patient information managed by the Oncology Institute and other healthcare providers has been compromised due to unauthorized third-party access. Approximately 3.4 million individuals may be affected across multiple healthcare organizations connected to the vendor. The breach potentially exposes sensitive healthcare data, impacting patient privacy and possibly regulatory compliance. No evidence of ransomware or other specific attack types has been reported. The incident affects trust in third-party healthcare technology providers and highlights risks in supply chain security.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The Oncology Institute and the third-party vendor are managing the incident response and have established a patient portal for affected individuals. Organizations relying on this vendor should monitor official communications and follow any recommended actions from the vendor or regulatory bodies. No specific patches or technical mitigations have been disclosed at this time.