China Software Developer Network data breach
The China Software Developer Network breach happened on December 21, 2011 and exposed 6,414,990 accounts. 3 kinds of data were exposed.
Overview
- Site
- csdn.net
- Breach date
- December 21, 2011
- Recorded on
- November 27, 2025
- Accounts exposed
- 6,414,990
- Exposed data
- Email addresses, Passwords, Usernames
- Risk score
- 66 out of 100
Risk based on the exposed data
This breach scores 66 out of 100. The score is driven mostly by Passwords, Email addresses, Usernames.
The risk score is a guide to how dangerous a breach is, judged by the kinds of data exposed. The number of accounts is not included.
Breaches from the same period
- Stratfor (2011-12-24, 859,777 accounts)
- Tianya (2011-12-26, 29,020,808 accounts)
- RuneScape Boards (2011-12-26, 222,762 accounts)
What affected users should do
- Change your China Software Developer Network password, and also change it on any other service where you used the same password. You can create a new one with the password generator.
- Turn on two-factor authentication for your login.
This site organizes publicly available information about data breaches. Data as of March 23, 2026. Breach dates are as originally listed; when only the month is known, the date is recorded as the 1st.