---
title: "Data breach at Quest Diagnostics"
description: "Quest Diagnostics, a US clinical laboratory company, says it learned on October 21, 2026 of unauthorized access to Quanum LSM. Its clients (physicians, hospital and medical office staff) use this platform to place test orders and look up results. The company believes some patient records were access"
canonical: https://inyourgeek.com/en/fuites-de-donnees/2026-10-23-quest-diagnostics
type: fuite-de-donnees
author: "Sébastien Soulier"
publisher: "InYourGeek"
language: en
datePublished: 2026-10-23
dateModified: 2026-10-23
---
# Quest Diagnostics

Data breach — Low

Quest Diagnostics, a US clinical laboratory company, says it learned on October 21, 2026 of unauthorized access to Quanum LSM. Its clients (physicians, hospital and medical office staff) use this platform to place test orders and look up results. The company believes some patient records were accessed, but the investigation is ongoing and neither the number of people affected nor the types of data have been determined. The system has been taken offline, law enforcement has been notified, and no group has claimed the attack so far.

| Fact | Value |
| --- | --- |
| Disclosed on | October 23, 2026 |
| Incident dated | October 21, 2026 |
| Sector | Healthcare |
| Country | United States |
| Cause | Undisclosed |
| Severity | Low |
| Status | Confirmed |

## Exposed data

- Other personal data

## What you can do

- You can ask the organisation exactly what was exposed about you (right of access), and complain to the DPA if no answer comes within a month.

## Sources

- [Quest Diagnostics confirms data breach exposed patient records](https://www.bleepingcomputer.com/news/security/quest-diagnostics-confirms-data-breach-exposed-patient-records/) — Bleeping Computer
- [Quest Diagnostics Inc. - Form 8-K](https://www.sec.gov/Archives/edgar/data/0001022079/000094787126000941/ss6979200_8k.htm) — SEC

_Entry built from the cited sources after a corroboration check, then reviewed before publication._

---

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