Description

Security researchers at runZero have identified seven vulnerabilities in FatFs, a widely used FAT/exFAT filesystem library deployed across embedded systems and IoT devices. Tracked as CVE-2026-6682 through CVE-2026-6688, the flaws range from Medium to High severity and affect numerous platforms, including ESP-IDF, STM32Cube, Zephyr RTOS, MicroPython, ArduPilot, RT-Thread, Mbed, Samsung TizenRT, and SWUpdate. The vulnerabilities impact devices such as industrial controllers, IoT products, drones, security cameras, ATMs, and other embedded systems that rely on removable storage. The vulnerabilities include integer overflows, buffer overflows, memory corruption, divide-by-zero conditions, information disclosure, stale cache handling, and denial-of-service issues. An attacker can exploit these flaws by supplying specially crafted FAT, exFAT, or GPT filesystem images through USB drives, SD cards, or automated update mechanisms. Successful exploitation could result in application crashes, information leakage, data corruption, or, in some cases, arbitrary code execution, particularly on devices with limited memory protection. Organizations using products that incorporate FatFs should identify affected devices, review embedded software versions, and apply vendor updates as they become available. Developers maintaining customized or vendored FatFs implementations should audit their code, validate file handling routines, and integrate upstream fixes after appropriate testing. Restricting the use of untrusted removable media, monitoring for abnormal filesystem activity, and strengthening physical access controls can further reduce the risk of exploitation until patches are fully deployed.