4M Leboncoin Immobilier Database

Data Breach Overview

In June 2026, a user known as ChimeraZ allegedly posted a database linked to Leboncoin Immobilier on darkforums.su. The dataset was advertised as containing approximately 4,035,710 lines and 1,103,720 phone numbers, with a total size of around 4.38 GB in JSON format.

The leaked data appears to relate to French real estate listings, including records from Leboncoin and several other property platforms. The claim remains unverified, and it is not yet clear whether Leboncoin itself was directly compromised or whether the data came from an external aggregator or third-party source. Independent reporting also noted that the actor suggested the source may be upstream rather than Leboncoin directly.

Where Was the Data Found?

The database was circulating on an underground forum, where the poster claimed it contained real estate listing data from multiple French websites. The forum post included download mirrors, which are not reproduced here.

According to the posted counts, the largest portion of the dataset was attributed to:

• leboncoin.fr: 3,578,184 lines
• pap.fr: 198,389 lines
• paruvendu.fr: 114,880 lines
• seloger.com: 87,701 lines
• Additional records from Ouest-France Immo, PAP Commerces, Vivastreet, Le Figaro Immobilier, Zero Agence, and other real estate sites.

The exposed fields appear to include listing references, ad URLs, transaction type, property type, postal codes, city information, mobile phone numbers, photos, surface area, number of rooms, prices, and listing descriptions.

Company Data Breach History

A quick search found previous public reporting about a March 2024 Leboncoin data exposure, described as a technical incident. That incident reportedly displayed some buyers’ full names, phone numbers, and email addresses to private sellers, while Leboncoin stated that passwords and banking information were not affected.

For this June 2026 incident, public reporting describes the claim as an alleged leak of around 4 million real estate listings and approximately 1.1 million phone numbers, but the breach has not been independently confirmed.

Impact and Risks

Even if much of the information comes from public real estate listings, the aggregation of phone numbers, locations, seller details, prices, and property descriptions creates privacy and security risks. Threat actors could use the data for targeted phishing, SMS scams, fraudulent property inquiries, impersonation of buyers or agents, spam campaigns, and social engineering.

Real estate data can be especially sensitive because it may reveal where people live, where they own property, what they are selling or renting, and how they can be contacted.

Recommendations for Users

Users who posted property listings on Leboncoin or related French real estate platforms should be cautious of unexpected calls, SMS messages, emails, or WhatsApp messages referencing their listings.

Users should avoid clicking links sent by unknown buyers or agents, verify communications directly through the official platform, enable two-factor authentication where available, use unique passwords, and monitor accounts for suspicious activity. Anyone receiving suspicious payment, courier, or identity-verification requests should treat them as potential scams.

What is InsecureWeb?

InsecureWeb is a Dark Web monitoring service that keeps track of recent data breaches and tracks their impact by monitoring the darkest places of the internet.

Our commitment lies in providing top-notch cybersecurity services to our clients. Through continuous monitoring of the dark web and advanced threat detection methodologies, we strive to identify potential breaches promptly, enabling swift response and mitigation efforts. With our state-of-the-art tools and expertise, we prioritize the confidentiality, integrity, and availability of our clients’ data.