Chess.com (2026) data breach
4,653,212 accounts exposed in a breach on 3 August 2026.
At a glance
4,653,212
Accounts exposed
3 August 2026
Date of the breach
13 September 2026
Added to the list
What happened
In August 2026, millions of records allegedly sourced from Chess.com were posted online. The data contained 7.3M rows with 4.6M unique email addresses, along with usernames, names, countries and data relating to users' Chess.com accounts. Analysis of the data suggested it had been obtained by scraping. When loaded into HIBP, 99% of the email addresses had already appeared in previous data breaches
What was exposed
- Email addresses. Email addresses were exposed. Expect more spam and phishing aimed at those addresses.
- Geographic locations. General locations were exposed. They add to a profile of you.
- Names. Names were exposed. Scammers use real names to make a message look personal.
- Usernames. Usernames were exposed. Together with a reused password they open accounts.
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.
Double Counter
In October 2026, the Discord server protection service Double Counter suffered a data breach attributed to a vulnerability in the Metabase analytics tool.
- Email addresses
- Geographic locations
- Names
- Usernames
Read what happened
Golf Canada
In mid-2026, hundreds of thousands of user records allegedly sourced from Golf Canada began circulating via Telegram.
- Dates of birth
- Email addresses
- Genders
- Geographic locations
- +2 more
Read what happened
Manchester Airports Group
In August 2026, Manchester Airports Group (MAG) disclosed a data breach impacting their services.
- Browser user agent details
- Email addresses
- Geographic locations
- IP addresses
- +4 more
Read what happened