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PatchSiren cyber security CVE debrief

CVE-2026-5768 Fourth Frontier CVE debrief

CVE-2026-5768 documents critical Bluetooth Low Energy (BLE) authentication and authorization failures in the Frontier X2 wearable device and its companion mobile application. Published on May 29, 2026, this HIGH severity vulnerability (CVSS 8.8) enables unauthenticated attackers within BLE range to exercise unauthorized control over device functions and inject fabricated health telemetry data. The vulnerability stems from two distinct but related weaknesses: the Frontier X2 device exposes critical GATT characteristics without requiring pairing authentication or authorization, while the Frontier X mobile application fails to properly authenticate BLE devices before accepting their data. Attackers can exploit these flaws to start or stop activities, trigger vibrations, cause denial-of-service conditions, fuzz characteristic values to induce unexpected behavior, and impersonate legitimate devices to inject false health metrics including breathing rate, heart rate, and strain data. The vulnerability is classified under CWE-306 (Missing Authentication for Critical Function). CISA has issued advisory ICSMA-26-148-01 addressing this medical device security concern. Organizations and users of Frontier X2 devices should monitor for vendor security updates and implement compensating controls to limit BLE exposure.

Vendor
Fourth Frontier
Product
Frontier X Android application
CVSS
HIGH 8.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-29
Original CVE updated
2026-05-29
Advisory published
2026-05-29
Advisory updated
2026-05-29

Who should care

Healthcare providers using Frontier X2 for patient monitoring, fitness and athletic training programs relying on Frontier X2 biometric data for performance decisions, individuals using Frontier X2 for personal health tracking, medical device security teams, and organizations with bring-your-own-device policies allowing wearable medical technology

Technical summary

The Frontier X2 device exposes critical GATT characteristics without BLE pairing authentication or authorization, allowing unauthenticated read/write access. The companion mobile application lacks BLE device authentication, permitting attacker device impersonation. Combined, these weaknesses enable unauthorized device control (activity manipulation, vibration triggering, DoS) and injection of fabricated health telemetry (breathing rate, heart rate, strain) into legitimate workflows. Attack requires adjacent network positioning (BLE range) with low complexity and no privileges. CVSS 3.1 score 8.8 reflects high impacts to confidentiality, integrity, and availability.

Defensive priority

HIGH

Recommended defensive actions

  • Contact Fourth Frontier Technologies through official support channels to inquire about firmware updates addressing BLE authentication and authorization controls
  • Monitor CISA ICS Medical Advisory ICSMA-26-148-01 for vendor-coordinated disclosure updates and remediation guidance
  • Disable BLE functionality on Frontier X2 devices when not actively required for medical monitoring purposes
  • Implement physical security controls to reduce BLE attack surface by limiting proximity of untrusted devices to Frontier X2 wearables
  • Verify integrity of health telemetry data in clinical or fitness workflows that incorporate Frontier X2 measurements, implementing cross-validation with independent measurement sources where patient safety decisions rely
  • Review and update mobile application to latest available version from official app stores once vendor patches are released
  • Consider network segmentation for mobile devices running Frontier X application to limit exposure to rogue BLE advertisements in controlled environments

Evidence notes

CVE description confirms unauthenticated BLE access to critical GATT characteristics without pairing authentication or authorization. CVSS vector AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H supports HIGH severity with attack vector adjacent network, low attack complexity, no privileges required, and high impacts across confidentiality, integrity, and availability. CISA ICS Medical Advisory ICSMA-26-148-01 provides official government coordination. CWE-306 (Missing Authentication for Critical Function) assigned as primary weakness. Vendor evidence points to Fourth Frontier Technologies based on reference domain analysis.

Official resources

2026-05-29