Personal Data Leak Monitor

China Software Developer Network data breach

6.41M accounts from China Software Developer Network (csdn.net) were exposed in this breach. Besides email addresses, it included passwords, which makes it a high-risk breach.

Breach date
December 21, 2011
Accounts
6,414,990
Added to the database
November 27, 2025

Was your email address in this breach?

Check if your email has leaked

We display where your address leaked and what went with it. We never store the address.

We don't store your address. It is checked right here against about 1029 breaches, including this one.

What leaked

Email addressesPasswordsUsernames

What to do now

  1. Please change that password, and anywhere you reused it
  2. Do not tap links in emails claiming to be that service
  3. Verify you have not reused that login anywhere

Tools that help with this breach

1PasswordPaidVisit the official site →(opens in a new tab)YubiKeyPaidVisit the official site →(opens in a new tab)

About this breach

In 2011, the China Software Developer Network (CSDN) suffered a data breach that exposed over 6M user records. The data included email addresses alongside usernames and plain text passwords.

Source: Have I Been Pwned (CC BY 4.0)

Similar breaches from the same period