McGraw Hill data breach
13,500,136 accounts exposed in a breach on 10 April 2026.
At a glance
13,500,136
Accounts exposed
10 April 2026
Date of the breach
16 April 2026
Added to the list
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 fi
What was exposed
- Email addresses. Email addresses were exposed. Expect more spam and phishing aimed at those addresses.
- Names. Names were exposed. Scammers use real names to make a message look personal.
- Phone numbers. Phone numbers were exposed. Expect scam calls and text messages, some of them pretending to be the organisation.
- Physical addresses. Home or postal addresses were exposed. They can be used to make a scam letter or a fake identity look real.
What to do now
It depends on what was exposed, so these steps follow the list above.
If your contact details were exposed
- Expect more spam, scam calls and phishing. Do not click links or open attachments in messages you did not expect.
- If a message mentions this breach, do not reply. Go to the organisation's own website or app instead of using a link in the message.
Whatever was exposed
- Check which other breaches include your own email address and phone number.
- Keep an eye on your accounts for a few months. Breached data is often used long after the breach.
- If you think someone is using your details, report it to the organisation and to your national cyber crime reporting service.
Check your own exposure
- Password leak check: find out whether a password has appeared in a breach. The password never leaves your browser.
- Free domain security scan: grade the email, DNS and website security of a domain you own.
Related breaches
Other breaches that exposed some of the same kinds of data.
Gîtes de France
In May 2026, the French holiday rental network Gîtes de France suffered a data breach affecting some of its departmental branches.
- Booking details
- Email addresses
- Names
- Phone numbers
- +1 more
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Crunchbase
In January 2026, the private company intelligence platform Crunchbase was targeted in a ShinyHunters "pay or leak" extortion attempt.
- Email addresses
- Employers
- Job titles
- Names
- +3 more
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Sharecare
In August 2026, the digital health company Sharecare was the target of a ShinyHunters "pay or leak" extortion campaign.
- Dates of birth
- Email addresses
- Employers
- Genders
- +6 more
Read what happened