CVE-2026-66875 Overview
CVE-2026-66875 affects the Mira hormone monitor device firmware version v1.7.1.47 build 01070147. The vulnerability allows a remote unauthenticated attacker within Bluetooth Low Energy (BLE) range of approximately 10 to 30 meters to silently rebind the device to an attacker-controlled account. Attackers can extract stored hormone measurements in cleartext, trigger a denial-of-service via malformed or undocumented command opcodes, and passively track the user via a static random BLE address that never rotates. The root cause is classified as Missing Authentication for Critical Function [CWE-306].
Critical Impact
An unauthenticated attacker within BLE range can hijack device ownership, exfiltrate cleartext hormone measurements, cause denial-of-service, and passively track the user.
Affected Products
- Mira Hormone Monitor Device Firmware v1.7.1.47 build 01070147
Discovery Timeline
- 2026-08-11 - CVE-2026-66875 published to NVD
- 2026-08-12 - Last updated in NVD database
Technical Details for CVE-2026-66875
Vulnerability Analysis
The Mira hormone monitor exposes several BLE-accessible operations without any authentication or authorization checks. An attacker within radio range can issue rebind commands that reassign the device to a paired account under attacker control. Once rebound, the device happily returns stored hormone measurement data as cleartext to the new controller. The firmware also lacks validation for command opcodes, allowing malformed or undocumented values to crash the device and produce a denial-of-service condition.
A separate privacy weakness compounds the impact. The device advertises a static random BLE address that never rotates, enabling passive location tracking of the user carrying or storing the device.
Root Cause
The underlying weakness is Missing Authentication for Critical Function [CWE-306]. Security-relevant BLE operations, including account rebinding, data retrieval, and command dispatch, execute without verifying the identity of the peer. The static BLE address is a design flaw that ignores established privacy guidance for BLE peripherals to periodically rotate resolvable private addresses.
Attack Vector
Exploitation requires only BLE proximity. The attacker uses a standard BLE-capable device to scan for the target peripheral, connect, and issue the unauthenticated rebind operation. Following the rebind, the attacker reads the hormone measurement characteristic and receives the plaintext values. The denial-of-service variant is achieved by writing malformed opcodes to a command characteristic, causing the firmware to hang or reset. Passive tracking requires no connection at all; the attacker simply logs the device's persistent BLE address as it appears in advertising packets.
Refer to the CISA ICS Medical Advisory and the GitHub CSAF Document for full technical detail.
Detection Methods for CVE-2026-66875
Indicators of Compromise
- Unexpected rebind or pairing events on the Mira device, particularly from unknown mobile applications or BLE central devices.
- Sudden loss of connectivity between the legitimate paired mobile app and the device.
- Device resets or crashes correlated with BLE activity from unknown nearby devices.
- Persistent BLE advertising address that does not rotate between sessions.
Detection Strategies
- Monitor BLE traffic in sensitive environments using a spectrum analyzer or BLE sniffer to identify unauthorized connection attempts to medical peripherals.
- Audit companion mobile application logs for unexpected rebind events or account reassignment notifications.
- Compare observed device BLE addresses across time; a static address across multiple advertising intervals indicates the tracking exposure applies.
Monitoring Recommendations
- Deploy BLE monitoring in clinical or home environments where hormone monitoring devices are used to detect abnormal pairing behavior.
- Track vendor advisories from the CISA ICS Medical Advisory portal for firmware updates addressing this issue.
- Correlate device disconnection events with proximity of unknown BLE peers.
How to Mitigate CVE-2026-66875
Immediate Actions Required
- Apply vendor-issued firmware updates as soon as they become available for the Mira hormone monitor.
- Restrict device use to trusted physical environments where unknown BLE peers are unlikely to be within 10 to 30 meters.
- Power the device off when not actively in use to prevent passive tracking and unauthorized rebinding.
Patch Information
At the time of publication, no fixed firmware version is listed in the enriched CVE data. Consult the CISA ICS Medical Advisory ICSMA-26-223-01 for the latest vendor mitigation guidance and any published firmware updates.
Workarounds
- Keep the device powered off outside of active measurement sessions to minimize BLE exposure.
- Use the device only in controlled, private environments away from untrusted BLE range.
- Avoid pairing the device in public locations where an attacker could observe or interfere with the pairing exchange.
- Regularly review the paired account status in the companion mobile application to detect unauthorized rebinding.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
