Personal Data Leak Monitor

Synthient Credential Stuffing Threat Data data breach

1.96B accounts from Synthient Credential Stuffing Threat Data were exposed in this breach. Besides email addresses, it included passwords, which makes it a high-risk breach.

Breach date
April 11, 2025
Accounts
1,957,476,021
Added to the database
November 6, 2025

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What leaked

Email addressesPasswords

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

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

During 2025, the threat-intelligence firm Synthient aggregated 2 billion unique email addresses disclosed in credential-stuffing lists found across multiple malicious internet sources. Comprised of email addresses and passwords from previous data breaches, these lists are used by attackers to compromise other, unrelated accounts of victims who have reused their passwords. The data also included 1.3 billion unique passwords, which are now searchable in Pwned Passwords. Working to turn breached data into awareness, Synthient partnered with HIBP to help victims of cybercrime understand their exposure.

Source: Have I Been Pwned (CC BY 4.0)

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