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Data breaches → Facebook

Was your data in the Facebook breach?

2019 · facebook.com · ~509,458,528 accounts exposedCritical severity · 8/10

Facebook (facebook.com) suffered a data breach in 2019 that exposed around 509,458,528 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 April 2021, a large data set of over 500 million Facebook users was made freely available for download. Encompassing approximately 20% of Facebook's subscribers, the data was allegedly obtained by exploiting a vulnerability Facebook advises they rectified in August 2019. The primary value of the data is the association of phone numbers to identities; whilst each record included phone, only 2.5 million contained an email address. Most records contained names and genders with many also including dates of birth, location, relationship status and employer.

Breach details sourced from Have I Been Pwned, the industry-standard breach database. 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 Facebook breach exposed and what each item actually enables:

Dates of birth

Date of birth is a permanent identifier used to verify identity by phone. Combined with a name and address it is often enough to impersonate you.

Phone numbers

Enables SIM-swap attacks (hijacking your number to intercept SMS codes), smishing, and voice scams that appear to come from your bank.

Location data

Reveals where you live, work or travel, which supports both targeted scams and physical-safety risks.

Names and usernames

Links this leak to your other accounts — a reused username lets anyone build a profile of you across platforms.

Email addresses

Puts you on spam and phishing lists, and confirms to attackers that you hold an account with this service — which makes impersonation emails more believable.

Also listed in this breach: Dates of birth, Email addresses, Employers, Genders, Geographic locations, Names, Phone numbers, Relationship statuses.

What to do if you were affected

These steps are ordered for this specific breach — the most urgent action given what leaked comes first.

  1. Dates of birth: Never confirm your date of birth to an inbound caller — hang up and dial the organisation back on a published number.
  2. Phone numbers: Move two-factor authentication off SMS to an authenticator app or passkey, and add a port-out PIN with your mobile provider.
  3. Location data: Review location sharing on the accounts you still hold with this service.
  4. Names and usernames: Search your usual username to see what else it exposes, and use distinct handles for sensitive accounts.
  5. Email addresses: Treat any message referencing this service with suspicion, and never act on links in unexpected emails.
  6. Check whether your own email appears in this breach — run a free scan to confirm before you spend time on the steps above.

How urgent is this now?

This breach is over 7 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.

Check if your email was exposed.Nullivo's free scan checks your own verified email against known breaches — including Facebook — in 30 seconds. No password, no signup, and we only ever scan your own email. Run your free scan →

Frequently asked questions

What data was exposed in the Facebook breach?

The Facebook breach exposed dates of birth, phone numbers, location data, names and usernames, email addresses. Date of birth is a permanent identifier used to verify identity by phone. Combined with a name and address it is often enough to impersonate you.

How many people were affected by the Facebook breach?

Around 509,458,528 accounts were exposed, making it one of the largest breaches ever recorded.

What should I do if I had a Facebook account?

Never confirm your date of birth to an inbound caller — hang up and dial the organisation back on a published number. 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 Facebook breach affected you, these breaches exposed comparable information — worth checking too, since leaked datasets are routinely combined.

See all breaches we cover →