---
schema_version: "secwatch.filing_event.v1"
accession: "0000927653-26-000247"
form_type: "8-K"
ticker: "MCK"
cik: "0000927653"
company_name: "MCKESSON CORP"
filed_at: "2026-08-28T20:05:30+00:00"
generated_at: "2026-08-28T20:08:32.638974+00:00"
event_type: "cyber"
sentiment: "negative"
materiality_score: 0.5
calibrated_materiality_score: 0.5
confidence: "high"
source: SEC EDGAR
---

# McKesson discloses cybersecurity incident on Aug 25, 2026; investigation early

## Summary
- Cybersecurity incident discovered Aug 25, 2026 affecting information systems; investigation in early stages.
- Company has not determined incident is material or likely to have material impact on financials or operations.
- Updates to be posted on company website at www.mckesson.com/cybersecurity as investigation proceeds.

## SEC filing metadata
- accession: 0000927653-26-000247
- form_type: 8-K
- ticker: MCK
- cik: 0000927653
- company_name: MCKESSON CORP
- filed_at: 2026-08-28T20:05:30+00:00
- event_type: cyber
- sentiment: negative
- materiality_score: 0.5
- calibrated_materiality_score: 0.5
- confidence: high
- sec_items: 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/927653/000092765326000247/0000927653-26-000247-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/927653/000092765326000247/mck-20260825.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000927653-26-000247
- JSON: https://secwatch.observer/filing/0000927653-26-000247.json
- Plain text: https://secwatch.observer/filing/0000927653-26-000247.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.