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44 disclosed this week · 26,355 on record

Kaiser Permanente Health Plan, Inc of Northern California

Disclosed Nov 7, 20164,432 affectedConfirmed

Official notice

On October 12, 2016, Kaiser Permanente upgraded its website, kp.org, which resulted in an incorrect configuration setting for caching data. This website upgrade affected several covered entities (CEs), including Kaiser Permanente Health Plan of Northern California. As a result of the error, some users who logged into the website may have had some of the protected health information (PHI) they viewed online saved into the cache where it could be seen by other visitors to the webpage. Kaiser Permanente was alerted to the incident and took action to repair the error. The breach affected approximately 4,432 individuals participating with this CE. The types of PHI involved in the breach included financial, clinical and demographical information. The CE provided breach notification to HHS, affected individuals, and the media. It also provided substitute notice. In response to the breach, the CE created a corrective action plan to help mitigate the chances of a misconfiguration error by educating the relevant IT staff, creating new processes, ensuring sign offs and approvals at appropriate points in the process, testing an outcome before going live, and engaged a subject matter expert. OC

What is known

People affected4,432 (as reported to HHS)
DisclosedNov 7, 2016
HappenedOct 12, 2016
AttackInsider
Data exposedNamesHealth
SectorHealthcare · US
StatusConfirmed

Sources

Notices filed

History of this record
attack2026-09-25
unknown to insiderby backfillSource
data_types2026-09-25
[] to ["names","health"]by backfillSource
records_basis2026-09-25
empty to hhsby backfillSource
records2026-09-25
empty to 4432by backfillSource
summary2026-09-25
empty to On October 12, 2016, Kaiser Permanente upgraded its website, kp.org, which resulted in an incorrect configuration setting for caching data. This website upgrade affected several covered entities (CEs), including Kaiser Permanente Health Plaby backfillSource
Added2026-09-25
First recordedby backfillSource

First seen 2026-09-25 (California AG), confirmed by California AG. Record counts are as reported. Not legal advice.

Everything about Kaiser Permanente Health Plan, Inc of Northern California