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Data breaches → Dennis Kirk

Was your data in the Dennis Kirk breach?

2021 · denniskirk.com · ~1,356,026 accounts exposedHigh severity · 7/10

Dennis Kirk (denniskirk.com) suffered a data breach in 2021 that exposed around 1,356,026 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 October 2024, almost 20GB of data containing 1.3M unique email addresses from motorcycle supplies store Dennis Kirk was circulated. Dating back to September 2021, the data also contained purchases from the online store along with customer names, phone numbers and postcodes. Dennis Kirk did not respond to multiple attempts to make contact about the breach.

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 Dennis Kirk breach exposed and what each item actually enables:

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: Email addresses, Geographic locations, Names, Phone numbers, Purchases.

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. Phone numbers: Move two-factor authentication off SMS to an authenticator app or passkey, and add a port-out PIN with your mobile provider.
  2. Location data: Review location sharing on the accounts you still hold with this service.
  3. Names and usernames: Search your usual username to see what else it exposes, and use distinct handles for sensitive accounts.
  4. Email addresses: Treat any message referencing this service with suspicion, and never act on links in unexpected emails.
  5. 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 data has been circulating for around 5 years, which means it has been copied, combined with other leaks and indexed by search tools many times over.

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 Dennis Kirk — 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 Dennis Kirk breach?

The Dennis Kirk breach exposed phone numbers, location data, names and usernames, email addresses. Enables SIM-swap attacks (hijacking your number to intercept SMS codes), smishing, and voice scams that appear to come from your bank.

How many people were affected by the Dennis Kirk breach?

Around 1,356,026 accounts were exposed, making it a large breach.

What should I do if I had a Dennis Kirk account?

Move two-factor authentication off SMS to an authenticator app or passkey, and add a port-out PIN with your mobile provider. 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 Dennis Kirk breach affected you, these breaches exposed comparable information — worth checking too, since leaked datasets are routinely combined.

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