BMO and Simplii Data Breach History

This page tracks the BMO and Simplii data breach history and cybersecurity incidents affecting BMO and Simplii (Canada). BreachHistory currently indexes 2 publicly disclosed or catalogued incidents spanning 2018, with approximately 180 thousand 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 BMO and Simplii 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.

Largest BMO and Simplii Data Breaches

The largest indexed incidents include the 2018 BMO/Simplii — 90k Canadian banking and the 2018 — BMO and Simplii: Poor security / misconfiguration, 90000 records. Record counts originating from threat actors or leak sites should be treated as estimates unless confirmed by BMO and Simplii or a regulator. Below is the list of large data breaches:

• 2018 2018 BMO/Simplii — 90k Canadian banking — about 90.0K records exposed · Catalogued incident
• 2018 2018 — BMO and Simplii: Poor security / misconfiguration, 90000 records — about 90.0K records exposed · Catalogued incident

What Information Was Exposed?

Depending on the incident, exposed data may include bank account details, health and medical (PHI) records, and other personal information (PII). The exact data varies between incidents, so review each breach page before assuming your information was affected.

BMO and Simplii Data Breach 2026

At the time of this update, no BMO and Simplii data breach has been catalogued for 2026. 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 BMO and Simplii 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 BMO and Simplii 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.