Was your data in the University of California breach?
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University of California (universityofcalifornia.edu) suffered a data breach in 2020 that exposed around 547,422 accounts. If you had an account, some of your personal data may be circulating in leaked databases. The fastest way to know is to check your own email — free, in about 30 seconds, no password required.
What happened
In December 2020, the University of California suffered a data breach due to vulnerability in in a third-party provider, Accellion. The breach exposed extensive personal data on both students and staff including 547 thousand unique email addresses, names, dates of birth, genders, social security numbers, ethnicities and other academic related data attributes. Further analysis is available in Exploring the Impact of the UC Data Breach. The data was provided to HIBP courtesy of Cyril Gorlla.
Breach record from Have I Been Pwned, CC BY 4.0. Risk analysis by Nullivo.
What was exposed, and why it matters
Not all breaches carry the same risk — what matters is which fields leaked. Here is what the University of California breach exposed and what each item actually enables:
Also listed in this breach: Dates of birth, Education levels, Email addresses, Ethnicities, Genders, Job titles, Names, Phone numbers, Physical addresses, Social security numbers.
What to do if you were affected
These steps are ordered for this specific breach — the most urgent action given what leaked comes first.
- Government identifiers
Consider a credit freeze or fraud alert with the credit reference agencies, and watch for accounts you did not open. - Sensitive personal characteristics
Under UK/EU GDPR you have a strong right to erasure here — exercise it with the service and with any site republishing the data. - Home addresses
Get your address removed from data brokers — they re-list roughly every four months, so this needs repeating. - Dates of birth
Never confirm your date of birth to an inbound caller — hang up and dial the organisation back on a published number. - Phone numbers
Move two-factor authentication off SMS to an authenticator app or passkey, and add a port-out PIN with your mobile provider. - Confirm you were actually in it
Run a free scan before you spend time on the steps above.
This breach put your details on data-broker sites
Because University of California exposed sensitive personal characteristics and home addresses, this is one of the breaches that feeds people-search and data-broker sites. Those sites scrape leaked databases, combine them with public records, and republish the result as a searchable profile — which is how a single breach turns into a permanent public listing. Removal works, but brokers typically re-list within about four months, so it has to be repeated.
See our broker-by-broker removal guides →
How urgent is this now?
This breach is over 6 years old. Old credentials still cause harm — leaked passwords from a decade ago are still tried against new accounts every day.
Remember: a breach can’t be “un-leaked” — once a database is out, it exists in countless copies. The goal is to make the leaked data useless: change what can be changed, lock down what can’t, and remove what has been republished.
Frequently asked questions
What data was exposed in the University of California breach?
The University of California breach exposed government identifiers, sensitive personal characteristics, home addresses, dates of birth, phone numbers, names and usernames, email addresses. The strongest identity-theft material there is — enough to open credit accounts or file fraudulent claims in your name.
How many people were affected by the University of California breach?
Around 547,422 accounts were exposed, making it a mid-sized breach.
What should I do if I had a University of California account?
Consider a credit freeze or fraud alert with the credit reference agencies, and watch for accounts you did not open. You can check whether your own email appears in this breach with a free Nullivo scan — no password required.
Breaches that exposed similar data
If the University of California breach affected you, these breaches exposed comparable information — worth checking too, since leaked datasets are routinely combined.