The OpenTable Breach Gave Hackers 10 Million Plaintext Passwords to Use Anywhere

HEROIC analysts uncovered the OpenTable breach while tracking credential activity across dark web forums and Telegram channels used by cybercriminals. The breach occured in August 2018 and exposed over 10.7 million records from OpenTable, the widely used US-based restaurant reservation platform. What stood out immediately was that passwords in this database were stored in plaintext with no hashing or encryption applied, meaning every single credential was readable the moment an attacker downloaded the file. With nearly 11 million email and password pairs in the open, the potential for ongoing harm from this breach is substantial.

What Attackers Can Do with 10 Million OpenTable Email and Password Pairs

Plaintext passwords from a platform as large as OpenTable are particularly valuable to attackers because the sheer volume makes automated attacks worthwhile. Criminals load these email and password pairs into credential stuffing tools and systematically test them against banking platforms, streaming services, email providers, and e-commerce sites. Because many people reuse passwords, even a small percentage of successful logins across 10 million records translates to hundreds of thousands of compromised accounts. This data has been shown to be circulating in Telegram channels where it is actively used in seperate ongoing attack campaigns.

What Was Exposed in the OpenTable Breach

• Email Address
• Plaintext Password

Why the OpenTable Breach Scale Makes It a Lasting Threat

Most data breaches fade from public attention quickly, but breaches of this size continue to fuel attacks for years. The OpenTable breach exposed enough credentials to be incorporated into massive combined dumps that attackers buy and sell repeatedly. Every time a user has not changed their 2018 password, that account remains a potential entry point for account takeover, identity theft, and financial fraud. The plaintext nature of the passwords means there is no technical barrier between an attacker and direct access to any account that still uses those old credentials.

How Database Breaches Work

A database breach occurs when an attacker finds a way into a company's back-end systems and extracts user data. Common methods include exploiting unpatched software vulnerabilities, using stolen administrator credentials, or finding databases that were accidentally left exposed on the internet. Once the data is copied, it is typically sold to other criminals before making its way into public breach dumps where it can be detected by security researchers monitoring for these exposures.

Check If Your Data Was Exposed

HEROIC's free breach scanner indexes more than 400 billion leaked records, including the full OpenTable breach dataset. Given that passwords in this breach were stored in plaintext, anyone whose email appears in this data should treat their credentials as fully compromised and change any matching passwords immediately. Run your free scan at HEROIC.com now to see if your information is at risk.