TaxAct Data Breach History
WebsiteTaxAct is a U.S. online tax-preparation and filing platform owned by Taxwell (Cinven).
This page shows all data breaches of TaxAct. View the complete breach timeline, records exposed, root causes, and AI breach risk score. BreachHistory tracks disclosed data breaches worldwide.
Data Breach Timeline — All TaxAct Breaches
TaxAct Data Breach Summary
This page tracks the TaxAct data breach history and cybersecurity incidents affecting TaxAct (United States). BreachHistory currently indexes 1 publicly disclosed or catalogued incident spanning 2026, with approximately 2.0 million records reported as exposed across all indexed events. These totals may include overlapping datasets or third-party estimates and should not be interpreted as unique affected users.
The TaxAct breach timeline includes major data breaches, cyber attacks, data leaks, credential exposures, API abuse, and other security incidents. Each incident provides details on the estimated records exposed, attack method, affected data types, and supporting public sources. Currently, 0 incidents are company-confirmed, while 1 remain unverified claims pending independent verification.
Largest TaxAct Data Breaches
The largest indexed incidents include the 2026 TaxAct — unauthenticated API claim; ~2M records acquired, 450k leaked (unveri…. Record counts originating from threat actors or leak sites should be treated as estimates unless confirmed by TaxAct or a regulator. Below is the list of large data breaches:
- 2026 2026 TaxAct — unauthenticated API claim; ~2M records acquired, 450k leaked (unverified) — about 2.0M records exposed · Unverified claim
What Information Was Exposed?
Depending on the incident, exposed data may include email addresses, phone numbers, names, payment card and financial account data, and other personal information (PII). The exact data varies between incidents, so review each breach page before assuming your information was affected.
TaxAct Data Breach 2026
At the time of this update, BreachHistory catalogues 1 2026 incident related to TaxAct. Most recent entry: 2026 TaxAct — unauthenticated API claim; ~2M records acquired, 450k leaked (unverified). New incidents are added as official disclosures, regulatory filings, or credible cybersecurity reports become available.
What To Do If You Were Affected
If you believe your account may have been involved in a TaxAct data breach, change any reused passwords, enable multi-factor authentication (MFA), monitor your account for suspicious activity, and be cautious of phishing emails or fake breach notifications.
This TaxAct breach history is maintained by BreachHistory using public disclosures, regulatory filings, security research, and clearly labelled third-party claims. For the complete breach timeline, records exposed, incident details, and AI Breach Risk Score, explore the sections on this page.