ProSomnus Sleep Technologies, a California-based manufacturer of oral appliances that treat obstructive sleep apnea, may have suffered a data security incident after a hacker group publicly claimed responsibility for an attack. Medical device companies that hold clinical, customer and employee information are expected to take reasonable steps to protect it from unauthorized access.
ProSomnus’s Data Breach Investigation
ProSomnus Sleep Technologies, known publicly as ProSomnus, designs and manufactures precision oral appliances used to treat obstructive sleep apnea and snoring, as an alternative to CPAP therapy. The company is based in California and works with dental and sleep medicine professionals. A business of this kind typically holds information about its employees, about the dental and medical practices that order its devices, and in some cases about the patients those devices are prescribed for.
According to an October 21, 2026 post on the dark web monitoring site Ransomware.live, the hacker group Brain Cipher claimed responsibility for an attack on ProSomnus, which was estimated to have taken place the same day. Breachsense, another cybersecurity monitoring platform, similarly reported that Brain Cipher claimed to be behind the attack, and said the claim allegedly involved roughly 100 gigabytes of data.
As of this writing, ProSomnus has not publicly confirmed that an attack occurred, and no additional information has been made public about the scope or nature of the incident. The sources reviewed do not say which systems were reached, whether any files were actually copied, or what kinds of records the group says it holds. This page does not fill those gaps with guesses.
Claims posted by ransomware groups on leak sites are widely treated as an early signal of a possible breach. Groups often post such claims to pressure a victim into paying a ransom or, if the victim does not pay, to publish stolen files as leverage. A claim alone does not prove that any particular person’s information was taken, but security researchers and monitoring services regularly treat these posts as a credible starting point for further inquiry, particularly when more than one independent platform reports the same claim.
Companies in the medical device and healthcare supply chain are a recurring target because they connect with many clinics and practices and may hold health-related information alongside business records. When personal information is confirmed to have been compromised, state breach notification laws generally require the organization to notify affected individuals, although the time between an initial claim, an internal investigation and a formal notice can stretch over weeks or months.
Because ProSomnus works with dental and sleep medicine providers, the people who could ultimately be affected may include current and former employees, customers, and affiliated healthcare providers or their patients. Whether any of those groups were affected has not been disclosed.
Attorneys are looking into whether ProSomnus maintained reasonable data security safeguards, and, if the incident is confirmed, whether stronger controls could have prevented or limited the exposure. Anyone connected to the company may wish to stay alert for any notice from ProSomnus about this reported incident and to keep any such notice for their records.
When Did This Breach Occur?
The suspected attack was first reported publicly on October 21, 2026, when the Brain Cipher hacker group’s claim of responsibility appeared on the dark web monitoring site Ransomware.live. The attack was estimated to have occurred on that same day. ProSomnus has not yet publicly confirmed the incident, so an official detection date, notification date or investigation timeline from the company is not available.
What Information Was Breached?
As of this writing, no specific categories of exposed information have been publicly confirmed by ProSomnus or by the monitoring platforms that reported the claim. Reports describing the incident have not detailed what types of personal, medical, employee or business information may have been accessed or stolen. This page will be updated if more information becomes publicly available.
What You Can Do
If you are connected to ProSomnus and are concerned about this reported incident, consider these steps:
- Watch for any official notice from ProSomnus about this incident and keep it, along with any enrollment details for protection services it offers.
- Place a free fraud alert or a credit freeze with Equifax, Experian and TransUnion, and get your reports free at annualcreditreport.com.
- Review bank, card and health insurance statements for anything you do not recognize.
- Be skeptical of unexpected calls, texts or emails that mention ProSomnus or this incident, and report suspected identity theft to the Federal Trade Commission at identitytheft.gov.
File a Data Breach Lawsuit Against ProSomnus
If you are a current or former ProSomnus employee, a customer, or a healthcare provider who works with ProSomnus, and you believe your information may have been exposed in this reported incident, you may have legal options for holding the company accountable for how it protected your data.
Contact us at Class Action U, where we’ll connect you with a lawyer skilled in class action lawsuits. If you’ve been contacted about this breach, received notice, or discovered you were impacted, fill out our quick, easy, and secure form to sign up. There is no cost to reach out to our legal partner and no obligation after speaking with someone from our team.
