Breach Database / McGraw Hill
Yes — McGraw Hill was breached.
- 13.5 million accounts affected
- Breach occurred 2026-04-10 · mheducation.com
- Verified entry in the Have I Been Pwned catalog
What happened
In April 2026, education company McGraw Hill confirmed a data breach following an extortion attempt. Attributed to a Salesforce misconfiguration, the company stated the incident exposed "a limited set of data from a webpage hosted by Salesforce on its platform". More than 100GB of data was later publicly distributed, containing 13.5M unique email addresses across multiple files, with additional fields such as name, physical address and phone number appearing inconsistently across some records.
What data was exposed
- Email addresses
- Names
- Phone numbers
- Physical addresses
What to do right now
- Be alert for smishing and SIM-swap attempts. Treat unexpected texts and "carrier" calls with suspicion; add a PIN/port-freeze with your mobile carrier.
- Watch for targeted phishing mail. A leaked home address makes postal and doorstep scams more convincing.
- Expect convincing phishing emails. Attackers use breached details to write personalized emails. Be suspicious of any message referencing this service.
- Check your other accounts on Have I Been Pwned. Your email address may appear in other breaches you don't know about yet.
- Monitor the apps you use going forward. Clearly watches the breach record for the companies behind your apps and alerts you the moment one appears.
Breach data from Have I Been Pwned. Listing here means the service appears in the public breach record — not that your personal data was affected.