---
title: "One Query Exposed 6,800 Meta Muse Chats: How a URL Architecture Flaw Leaked Banking Data and HR Secrets"
description: "Claroc researchers discovered that due to a URL architecture flaw in Meta Muse, 6,800 private chats were exposed in public DNS databases. The company temporarily blocked the linking feature following a leak of banking data and HR documents."
date: 2026-10-21T13:23:51.591Z
lang: en
url: https://xab.info/en/posts/meta-muse-chat-leak-6800-links-pdns
tags: [meta, ai-security, data-leak, muse, privacy, cybersecurity]
author: "Alexander Buran"
publisher: "XAB.info"
---

# One Query Exposed 6,800 Meta Muse Chats: How a URL Architecture Flaw Leaked Banking Data and HR Secrets

![Fluffy white toy sitting at a desk looking at a laptop with Meta Muse chat](https://xab.info/media/2026/10/21/meta-muse-utechka-chatov-6800-svyazey-pdns/meta-muse-utechka-chatov-6800-svyazey-pdns-1.webp)

## Key Points

- A single basic query collected 6,800 public links to private Meta Muse chats via passive DNS databases
- The leak occurred due to an architectural flaw: the chat name was embedded in the URL subdomain
- Banking data, HR notes, financial reports, and employee calendars were exposed to the public
- Meta temporarily blocked the creation of public links in Muse
- This is the second security incident for Muse in a month, following a zero-day vulnerability found three weeks prior

Meta has temporarily disabled the public link-sharing feature in its AI agent Muse after cybersecurity experts from Claroc discovered a massive leak of private user conversations. According to researchers, unauthorized individuals could find and read other people's chats that were never intended for public viewing. Gathering vulnerable links required no complex hacking attacks—a single basic query was enough to track down and collect 6,800 links to Muse chats created by users to share information.

### Architectural Flaw: Chat Name in Subdomain

The root of the problem lies in the URL architecture that Meta's developers built into the Muse service. Unlike the standard approach where services generate links with a random, long string of characters that is virtually impossible to guess, in Muse's case, the chat name was directly embedded into the address's subdomain. Examples of such links look like home-sale-budget-9f21c8a3.cf.metaaiusercontent.com or q3-revenue-review-7b1e42f0.cf.metaaiuser. When a recipient opened such a link, the subdomain information was instantly recorded in public passive DNS (pDNS) databases, becoming accessible to anyone who knows how to query them. Researchers dubbed this phenomenon GhostShares—pages that open for people who were never sent the links.

### What Exactly Leaked: From Bank Accounts to Vacation Calendars

During a spot-check of several hundred open pages, Claroc recorded a wide range of sensitive data. Among them were a candidate's HR notes while preparing for a confidential executive search call for an advanced AI lab, which listed the internal contact name and meeting time. An internal financial revenue report for a national marketing company with a note for the CEO was also publicly exposed. Of particular concern was banking data: a small business owner's loan application detailing a specific amount, as well as a task list with fraud alerts from the bank, including partial account numbers, amounts, and transaction times. Additionally, researchers found a realtor's internal report with two exact property addresses, yield, revenue, and mortgage payment data, as well as a company employee's complete vacation schedule detailing the absence dates of dozens of workers by last name.

### Timeline: From Bug Bounty to Meta’s Response

Claroc experts reported the issue through the Bug Bounty program back on October 8, 2026, but received no response from Meta for a long time. Only after journalists contacted the company for comment did Meta announce a temporary freeze on the link-sharing feature. In an official statement, the tech giant's representatives emphasized: «We opened the bug bounty program for Muse so researchers could expose various scenarios and help us improve the product. Users can share specific Muse materials. However, we have paused the functionality while we study the report and consider changes on how these links can be discovered.» At the time of publication, creating new public links in Muse is completely blocked.

### Second Incident in a Month and the Privacy Paradox

The current leak has become the second major security incident for the Muse application in a short period. Just three weeks earlier, a zero-day vulnerability was discovered in the AI app that allowed third-party programs to hijack control of a user account. The paradox of the situation is compounded by the fact that a month ago, Meta CEO Mark Zuckerberg publicly claimed that Muse was «built from the ground up with a focus on privacy and security.» Meanwhile, the assistant itself requires deep access to users' personal accounts to perform actions—such as filling out forms, making bookings, and processing payments, making the consequences of such leaks especially sensitive for end users.

## Fact-Check & Sources

- [Скандал с безопасностью Meta: как один запрос слил в сеть тысячи чатов Muse](https://www.rbc.ua/ukr/news/skandal-iz-bezpekoyu-meta-k-odin-zapit-vidkriv-1792586190.html) - The primary source contains all key facts: 6,800 links, the pDNS mechanism, leaked data categories, the Bug Bounty date (October 8), Meta's statement, and the context of the second incident. Meta's official quote is quoted verbatim.

## FAQ

### How exactly were other people's Muse chats accessed?

Meta developers embedded the chat name into the URL subdomain. When a recipient opened the link, the subdomain data was recorded in public passive DNS databases, allowing any researcher to find them with a single query.

### How many chats were exposed to the public?

Claroc researchers collected 6,800 links to Muse chats using a single basic query to public DNS databases.

### What did Meta do after discovering the leak?

The company temporarily suspended the public link creation feature in Muse and stated it is reviewing the report and considering changes to link discovery architecture.

### When did researchers notify Meta about the vulnerability?

Claroc experts submitted the report via the Bug Bounty program on October 8, 2026. Meta responded only after journalists reached out.

### Is this the first security incident involving Muse?

No. Three weeks prior to the link leak, a zero-day vulnerability was discovered in Muse that allowed third-party programs to hijack user account control.