McKesson is investigating a cybersecurity incident after ShinyHunters claims patient data theft

Databreaches •Dissent • August 29, 2026

Lawrence Abrams reports: Healthcare and pharmaceutical distribution giant McKesson has disclosed a cybersecurity incident involving unauthorized access to third-party applications and data theft, with the ShinyHunters extortion group claiming it stole 284 million patient data records. McKesson is a major U.S. healthcare company and pharmaceutical distributor that provides medicines, medical supplies, technology, and services to... Source

The full story

This article is one source in a clustered incident — the cluster page carries the summary, timeline and every other outlet covering it.

McKesson Cybersecurity Breach Involves 284 Million Patient Records McKesson, a major healthcare and pharmaceutical distributor, disclosed a cybersecurity incident involving unauthorized access to third-party applications and the theft of 284 million patient data records. The ShinyHunters extortion group claimed responsibility, stating they accessed the data through voice phishing (vishing) attacks targeting McKesson employees. The breach was discovered on August 25, 2026, and McKesson reported it in a Form 8-K filing with the SEC. The company has activated incident response protocols and is investigating the full scope of the incident. Customers may experience intermittent service degradation as a result of the attack. McKesson has not yet disclosed which third-party applications were compromised or the specific data that was stolen. The investigation is ongoing, and updates will be provided as more information becomes available. 21 sources 66

Extracted Entities

McKesson is investigating a cybersecurity incident after ShinyHunters claims patient data theft

The full story

Extracted Entities

Attack Types (1)

Companies (1)

Industries (2)

MITRE ATT&CK (1)