Auth bypass in Fourth Frontier X2
CVE-2026-5768
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.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (34.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Fourth Frontier X2 — versions All versions
- Fourth Frontier X Android Application — versions 0
- Fourth Frontier X iOS Application — versions 0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-5768?
- CVE-2026-5768 is a high-severity vulnerability in Fourth Frontier X2, classified under Missing Authentication for Critical Function. CVSS score: 8.8/10. Published 2026-05-29.
- How severe is CVE-2026-5768?
- High severity. CVSS v3 base score is 8.8 out of 10.