What To Do After a Data Breach: Your 2026 Action Plan

A series of major breaches has marked 2026 — leaked credentials tied to Fortinet/FortiGate firewall devices, Kodak, a third party connected to Nintendo, and the long tail of the 23andMe incident have all made headlines. If you're reading this wondering "was I caught up in one of these, and what now?", this is the calm, practical checklist to work through. None of it requires technical skill, and the most important steps take only a few minutes.

The short answer

• Check if you're affected with Have I Been Pwned and any official notice from the company.
• Change the leaked password — and every account where you reused it.
• Turn on 2FA so a stolen password alone can't log in.
• Stay alert for phishing that exploits the breach, and freeze your credit if identity data was exposed.
• Fix it for good: a unique password per account, stored in a password manager.

Step 1 — Find out whether you're affected

Don't panic, and don't guess. There are two trustworthy ways to know:

• Have I Been Pwned (haveibeenpwned.com) is a free, well-known service that checks your email address or phone number against a database of known breaches. It tells you which breaches your address appeared in, so you know exactly which accounts to prioritise.
• The official notification. Companies that suffer a breach are generally required to inform affected users. Read it for the specifics — what data was exposed (just email? passwords? payment info?) determines how serious it is for you.

Be careful here: post-breach is exactly when fake "you were breached" emails spread. Never log in through a link in such a message. Go to the service directly.

Step 2 — Change the password (and stop the chain reaction)

Change the password on the affected account first. Then — this is the step people skip — change it on every other account where you used the same or a similar password. Attackers take credentials leaked in one breach and try them across hundreds of other sites automatically. That's credential stuffing, and reused passwords are what make it work.

Each replacement password should be long, random, and unique. Don't just bump a number on the end of the old one — attackers and their tools guess those small variations easily. Start with your most important accounts: email, banking, and anything tied to your payment cards. Work outward from there to social media, shopping, and the dozens of sign-ups you've forgotten about over the years.

Step 3 — Turn on two-factor authentication

Once the password is changed, add a second lock. With two-factor authentication switched on, even a future leak of your password won't be enough to log in — an attacker would also need the code from your authenticator app or your hardware key. Prioritise your email account first (it can reset everything else), then banking and your password manager. Where you can choose, prefer an authenticator app or a hardware key over SMS codes, which are the weakest form of 2FA. It takes a couple of minutes per account and closes the door that a leaked password leaves open.

Step 4 — Watch your money and your inbox

• Monitor financial accounts. Check bank and card statements for unfamiliar charges for at least a few months. Set up transaction alerts if your bank offers them.
• Expect targeted phishing. Now that your details are out there, you'll likely see convincing scam messages. Treat every "secure your account" email as suspect and verify by opening the service yourself.
• Freeze your credit if identity data leaked. If a Social Security number, government ID, or bank details were exposed, a credit freeze stops fraudsters opening new accounts in your name. It's free to place and lift.

The real long-term fix

Breaches at companies aren't something you can prevent — but you can make them harmless to you. The single change that matters most is a unique password for every account, so one leak never spreads. Remembering dozens of strong, random passwords by hand is impossible, which is why a password manager exists: it generates and stores them, fills them in for you, and many can monitor known breaches and tell you precisely which of your logins to change.

The bottom line

A breach is alarming, but the response is straightforward: check whether you're affected, change the leaked password and any you reused, turn on 2FA, and stay sharp for phishing and fraud. Then close the door for good by giving every account its own unique password through a manager. Do the urgent steps today, and the 2026 wave of breaches becomes a scare instead of a disaster. Next, learn how 2FA works and how attackers exploit reused logins in credential stuffing.