Quest Diagnostics says unauthorized party accessed Quanum LSM system and certain patient records

Quest Diagnostics disclosed in an SEC Form 8-K filing on October 22, 2026 that it learned on October 21 that an unauthorized party had accessed its Quanum LSM system, which certain clients use to place test orders and receive and look up results. The company believes certain patient records were accessed. The full scope of the unauthorized access remains under investigation.

Quest said it promptly initiated its incident response procedures, notified federal law enforcement, and engaged external cybersecurity experts. The incident has not materially disrupted its business operations or its ability to serve patients. No record count has been stated, so this is prepared as a Cybersecurity item, not a Breaches add.

Sources: Kalkine; Reuters via WNCY