Adpost data breach: 3.3M accounts exposed
Severity: medium · Patch status: no-fix-needed · Since 2025-10-07
In February 2025, data obtained from an earlier Adpost breach surfaced. The dataset contained 3.3M records including email addresses, usernames, and display names. Adpost later published a disclosure notice and advised they'd forced a credential refresh, among other actions. Exposed data: email addresses, names, usernames. The breach dates from Feb 14, 2025; Have I Been Pwned loaded it on Oct 7, 2025.
What to do
- If you had a Adpost account, change its password and the password of any other account that reused it.
- Turn on multi-factor authentication wherever it is offered.
- Check whether your addresses are in this breach at https://haveibeenpwned.com.
Sources
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