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Response snapshot Oct 27, 2026, 02:52 UTC

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Disclosed incidenthibp-synthientcredentialstuffingthreatdata

Synthient Credential Stuffing Threat Data breach: 1,957,476,021 accounts exposed

During 2025, the threat-intelligence firm Synthient aggregated 2 billion unique email addresses disclosed in credential-stuffing lists found across multiple malicious internet sources .

At a glance

Sources
1 source

What to do

If you or your organization used this service, change reused passwords, watch for phishing that uses the exposed data, and check the disclosure for the organization's guidance.

Read Have I Been Pwned: Synthient Credential Stuffing Threat Data (opens a new tab)

What happened

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.

Sources

  1. Primary source

    Have I Been Pwned: Synthient Credential Stuffing Threat Data (opens a new tab)

    Verified breach loaded into Have I Been Pwned: account count, exposed data types, and dates.

    Published Checked

  2. Primary source

    Have I Been Pwned breach API (opens a new tab)

    The breach list that supplied this entry.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2025, November 8). Synthient Credential Stuffing Threat Data breach: 1,957,476,021 accounts exposed. https://kevwire.com/record/hibp-synthientcredentialstuffingthreatdata

MLA

"Synthient Credential Stuffing Threat Data breach: 1,957,476,021 accounts exposed." KEVWire, 8 Nov. 2025, kevwire.com/record/hibp-synthientcredentialstuffingthreatdata.

Chicago

KEVWire. "Synthient Credential Stuffing Threat Data breach: 1,957,476,021 accounts exposed." Last modified November 8, 2025. https://kevwire.com/record/hibp-synthientcredentialstuffingthreatdata.

Evidence summary (plain text)

Synthient Credential Stuffing Threat Data breach: 1,957,476,021 accounts exposed (Nov 6, 2025).
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.
Sources:
Have I Been Pwned: Synthient Credential Stuffing Threat Data: https://haveibeenpwned.com/Breach/SynthientCredentialStuffingThreatData
Have I Been Pwned breach API: https://haveibeenpwned.com/api/v3/breaches
Record ID: hibp-synthientcredentialstuffingthreatdata.
Record origin: Ingested record.
AI evidence: Not assessed.
About this data

This record was ingested from a data source. Retrieved: Oct 27, 2026, 02:25 UTC. Ingestion is not an independent editorial investigation.

Verified by Have I Been Pwned. Breach date: 2025-04-11; loaded 2025-11-06. Exposed data: Email addresses, Passwords. Counts are accounts in the loaded data, not necessarily distinct people.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

Record JSON

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Record details

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