Virtual Event: CISO Forum Virtual Summit 2026 Day 2 - Join the Livestream
Connect with us

Hi, what are you looking for?

SecurityWeekSecurityWeek

Data Breaches

Quest Diagnostics Data Breach Exposed ‘Certain Patient Records’

In a regulatory filing, Quest Diagnostics reported unauthorized access to its Quanum Lab Services Manager, a platform where certain clients can place test orders.

Data breach

Medical laboratory operator Quest Diagnostics said it learned of a cyber breach of one of its systems this week, likely compromising some records for patients.

In a Thursday regulatory filing, Quest Diagnostics reported “unauthorized access” to its Quanum Lab Services Manager, a platform where certain clients can place test orders and receive or look up their results. The company said it discovered the hack on Wednesday and notified federal law enforcement.

How many patients and which particular records have been affected is still unknown. Quest Diagnostics said it believes “certain patient records” were accessed in the breach, but that the full scope remains under investigation.

The New Jersey-based company said it’s also working with external cybersecurity experts to assist in its response.

Quest Diagnostics has seen hacks impacting patient records before. In 2016, for example, the company said data including lab results and contact information of about 34,000 people was exposed in another online breach. And in 2019, other personal information belonging to about 11.9 million Quest patients was affected after a separate hack at American Medical Collection Agency, a billing collections service provider.

Cyberattacks are on the rise across industries. Beyond healthcare, other breaches have recently disrupted anything from supermarket chains to core education applications.

Advertisement. Scroll to continue reading.

Governments and companies worldwide are working more broadly on online security updates. Urgency erupted this week, after an AI-assisted discovery of vulnerabilities in a programming language called PHP, which is vital to 70% of websites globally.

Outages and limited service have continued for many as firms rush to patch those risks. But based on the company’s investigation, Quest Diagnostics confirmed to The Associated Press Thursday that its cyber breach was not related to the PHP issue.

Related: 970,000 Medi-Cal Members Affected by Paradigm Healthcare Data Breach

Related: Hackers Steal 1.8 Million Records From Nikkei

Related: One Compromised Login Exposed Millions of California Students’ Records

Written By

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing for the latest cybersecurity threats, trends, and expert insights.

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

NOW LIVE: CISO Forum 2026 Summit

Join as we bring together CISOs, senior cybersecurity executives, practitioners, industry experts, and other security leaders to share practical experience and examine the issues shaping enterprise cybersecurity strategy.

Register

Join to learn the four levels of architecting security into the agentic SDLC – from securing the code your developers' agents write to running a coordinated system of security agents you've built yourself.

Register

People on the Move

Tal Kapulnik has been named CMO at Terra Security.

Cloudflare has appointed Christian Smith as President of Revenue.

Doran Stienike has become CIO at Presidio.

More People On The Move

Expert Insights

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest cybersecurity news, threats, and expert insights. Unsubscribe at any time.