Quest Diagnostics discloses unauthorized access to lab ordering and results system
Quest Diagnostics has detected unauthorized access to its Quanum Lab Services Manager platform, exposing patient health and identifiable information.
Quest Diagnostics disclosed that an unauthorized party accessed its Quanum Lab Services Manager system, a platform healthcare providers use to place test orders and view lab results. According to a company incident update released on October 22, 2026, Quest temporarily paused access to the affected system upon discovering the intrusion while keeping core business operations running.[1][3]
The diagnostic testing giant confirmed that the compromised data included patient health information and patient identifiable information from within Quanum LSM, though other internal systems were unaffected. The full scope of the breach remains under investigation, and the total number of patients whose records were accessed has not yet been determined.[2][3][4]
The company reported the unauthorized access in a filing to shareholders and stated it would issue formal breach notifications as required by applicable law. According to commentator Andrew Curran, Quest Diagnostics provides diagnostic testing services to roughly half of all U.S. hospitals and physicians.[1][3]
Key facts
- Quest Diagnostics detected unauthorized access to its Quanum Lab Services Manager (LSM) system, used by clinicians to order tests and look up results.
- The company confirmed that Patient Health Information (PHI) or Patient Identifiable Information (PII) within Quanum LSM was accessed during the incident.
- Quest Diagnostics paused access to the Quanum LSM system following the discovery, while core business operations continued operating.
- The total number of patients affected has not yet been specified as an investigation remains ongoing.
- Quest Diagnostics disclosed the incident in a filing to shareholders.
- According to Andrew Curran, Quest Diagnostics serves roughly half of U.S. hospitals and physicians.
Sources · 4 sources
- TW
The Washington Post@washingtonpostPost on X ·
Quest Diagnostics, one of America’s largest lab diagnostic companies, disclosed in a filing to shareholders that it learned of unauthorized access to a system used by doctors and other health care professionals to order tests and view lab results. https://t.co/zVkTqZATxY
Open source - SE
SecurityWeek@SecurityWeekPost on X ·
Quest Diagnostics Reports Cyber Breach Affecting ‘Certain Patient Records’ https://t.co/nvc6yVhnOQ
Open source - AC
Andrew Curran@AndrewCurran_Post on X ·
Quest Diagnostics has been hacked. Patient data was exposed. They serve roughly half of U.S. hospitals and physicians. Investigation ongoing. https://t.co/BSJ2fmn329
Open source - PO
Polymarket@PolymarketPost on X ·
JUST IN: Quest Diagnostics reports a cybersecurity breach potentially exposing sensitive patient records, with the number of affected patients still unknown.
Open source