An out‑of‑bounds heap write occurs during log replay when a FAT image with fault tolerance is mounted. The write is attacker‑positioned and attacker‑valued, reaching the FX_MEDIA driver callback and enabling control of the instruction pointer. This flaw, classified as CWE‑1284 and CWE‑787, can allow an attacker to execute arbitrary code with the privileges of the firmware.

The vulnerability affects the Eclipse ThreadX FileX file system component from the Eclipse Foundation. No specific product versions are listed in the CVE, so any installation of FileX that accepts fault‑tolerant FAT images may be impacted.

With a CVSS score of 7.8, the vulnerability poses a significant risk. EPSS data is not available, and the issue is not listed in CISA’s KEV catalog. The likely attack vector involves an attacker delivering a crafted FAT image to an embedded device that mounts it, enabling local escalation to arbitrary code execution. The absence of a publicly available patch requires careful assessment of whether such images can be introduced to the affected system.