Data breach

McKesson data breach

6,404,340 accounts · breached August 21, 2026

Have I Been Pwned treats this breach as sensitive: it does not reveal publicly whether a particular address is in it. Only the owner of an address can check, after verifying it.

What happened

In August 2026, healthcare and pharmaceutical company McKesson was targeted in a ShinyHunters "pay or leak" extortion campaign. The group subsequently published a substantial corpus of data they alleged was sourced from the company, which included 6.4M unique email addresses among other personal and corporate data attributes. The impacted data related to a range of individuals and roles, including marketing campaign recipients, patients, staff and healthcare provider contacts. In McKesson's disclosure notice, the company advised it had identified unauthorised access to "certain third-party applications and the exfiltration of certain data was associated with a subset of customers within our Oncology & Multispecialty and Medical-Surgical business units", but had "reasonable assurance of no ongoing unauthorized activity".

Description by Have I Been Pwned

What data leaked

  • Dates of birth
  • Email addresses
  • Employers
  • Genders
  • Names
  • Personal health data
  • Phone numbers
  • Physical addresses

What to do if you had an account

  1. Turn on two-step sign-in. Enable two-factor authentication where the service offers it, preferably with an authenticator app or a passkey. A leaked password alone is then not enough to get in.
  2. Expect targeted phishing. Leaked contact details are used to write convincing fake messages that mention the breached company or your real name. Do not click links in unexpected emails or texts about this account; go to the site by typing its address.
  3. Watch for scam calls and SIM swaps. Be suspicious of calls and texts that claim to be from your bank or a courier. Ask your mobile operator for a port-out or SIM-change PIN if it offers one.
  4. Guard against identity fraud. Identity documents and dates of birth cannot be changed like a password. Consider a credit freeze or fraud alert where your country offers one, and be wary of anyone who 'verifies' you using those details.
  5. Sensitive personal data. This breach includes sensitive categories of personal data. Scammers and blackmailers use such details to pressure people. Do not pay, and report extortion attempts to the police.

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