Was your data in the Comcast breach?
Check whether your email address was in it
Check my exposureFree. No password — we email you a six-digit code. This breach and every other one your address appears in.
Comcast (comcast.net) suffered a data breach in 2015 that exposed around 616,882 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 November 2015, the US internet and cable TV provider Comcast suffered a data breach that exposed 590k customer email addresses and plain text passwords. A further 27k accounts appeared with home addresses with the entire data set being sold on underground forums.
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 Comcast breach exposed and what each item actually enables:
What to do if you were affected
These steps are ordered for this specific breach — the most urgent action given what leaked comes first.
- Passwords
Change this password everywhere you have reused it, starting with your email account — whoever controls your email can reset everything else. - Home addresses
Get your address removed from data brokers — they re-list roughly every four months, so this needs repeating. - Email addresses
Treat any message referencing this service with suspicion, and never act on links in unexpected emails. - 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 Comcast exposed 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 11 years old. Old credentials still cause harm — leaked passwords from a decade ago are still tried against new accounts every day.
Passwords are the reason breach age matters less than people expect. Leaked credentials are compiled into wordlists that get tried against new services for years afterwards, so a password exposed here is unsafe to use anywhere, ever again.
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 Comcast breach?
The Comcast breach exposed passwords, home addresses, email addresses. Attackers replay leaked passwords across other sites (“credential stuffing”). Because most people reuse passwords, one leak often unlocks email, shopping and banking accounts elsewhere.
How many people were affected by the Comcast breach?
Around 616,882 accounts were exposed, making it a mid-sized breach.
What should I do if I had a Comcast account?
Change this password everywhere you have reused it, starting with your email account — whoever controls your email can reset everything else. 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 Comcast breach affected you, these breaches exposed comparable information — worth checking too, since leaked datasets are routinely combined.