CVE-2021-35954: Fastrack Reflex 2.0 Firmware

High severity, CVSS 8.1. EPSS: 0.3% chance of exploitation in the next 30 days.

fastrack Reflex 2.0 W307S_REFLEX_v90.89 Activity Tracker allows physically proximate attackers to dump the firmware, flash custom malicious firmware, and brick the device via the Serial Wire Debug (SWD) feature.

Affected products

• Fastrack Reflex 2.0 Firmware: version 90.89 only

Published 2022-12-26. Last modified 2026-06-17.