---
title: Quest Diagnostics says an attacker got into its Quanum Lab Services Manager and likely accessed certain patient records | ctxsec
url: https://ctxsec.com/items/quest-diagnostics-quanum-lsm-breach-oct-2026
description: ""
status: "confirmed (Quest Diagnostics Form 8-K, filed Oct 22); scope still under investigation"
published: 2026-10-22
---

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[← Cybersecurity News](/news) · [markdown](/items/quest-diagnostics-quanum-lsm-breach-oct-2026.md)

confirmed (Quest Diagnostics Form 8-K, filed Oct 22); scope still under investigation

2026-10-22

### Quest Diagnostics says an attacker got into its Quanum Lab Services Manager and likely accessed certain patient records

In an 8-K filed early on **Oct 22**, Quest Diagnostics said it learned on **Oct 21** of unauthorized access to its **Quanum LSM** system, which some clients use to place test orders and to receive and look up results. Quest says it believes an unauthorized party **accessed certain patient records**; the full scope is still under investigation. It has notified federal law enforcement, brought in outside incident responders, and says operations and patient service weren't materially disrupted. Quest hasn't said how the attacker got in or how many people are affected.

**If you're a Quest client:** review which of your staff accounts use Quanum LSM, reset those credentials, check recent result look-ups for anything unusual, and expect follow-up from Quest about notification duties under HIPAA.

Sources: [Quest Diagnostics Form 8-K (Item 8.01), Oct 21 event, via StockTitan](https://www.stocktitan.net/sec-filings/DGX/8-k-quest-diagnostics-inc-reports-material-event-f35330d61b13.html) · [AP News: Quest Diagnostics reports cyber breach affecting certain patient records](https://apnews.com/article/quest-cyber-breach-82dbe1fa6ba06cf6514bc16f73e64fe1)