What’s Vulnerable › Vulnerabilities

CVE-2026-5768: Fourth Frontier Frontier X Mobile Application, Frontier X2 Missing Authentication for Critical Function

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-29 · updated 2026-07-22
• Weakness: CWE-306

Description

The Frontier X2 device allows unauthenticated BLE read/write access to critical GATT characteristics without enforcing pairing authentication or authorization. This allows attackers within BLE range to perform unauthorized control of device functions, including starting/stopping activities, triggering vibrations, causing denial-of-service conditions, and fuzzing characteristic values to induce unexpected behavior. Additionally, the Frontier X mobile application lacks proper BLE device authentication, allowing attackers to impersonate a legitimate Frontier X2 device and connect to the application. By cloning BLE advertisements and exposing expected GATT characteristics, attackers can manipulate activity states and inject fabricated health telemetry such as breathing rate, heart rate, strain, and other health-related data into the mobile application.

Affected products

• Fourth Frontier Frontier X2: all versions
• Fourth Frontier Frontier X Android application: before 15.0.0 — fixed in 15.0.0
• Fourth Frontier Frontier X IOS application: before 25.0.0 — fixed in 25.0.0

How to fix

Upgrade to a fixed version: Fourth Frontier Frontier X Android application 15.0.0; Fourth Frontier Frontier X IOS application 25.0.0. Check the vendor advisory for mitigations.

References

• https://fourthfrontier.com/pages/contact-us
• https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsma-26-148-01.json
• https://www.cisa.gov/news-events/ics-medical-advisories/icsma-26-148-01

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