FileX fault-tolerant log replay writes past the destination sector when mounting a crafted FAT image

published 2026-10-20 19 d ago modified 2026-10-20 19 d ago also EUVD-2026-104999

cvss: 7.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits: 0; none known

Mounting an attacker-controlled FAT image with fault tolerance enabled causes an out-of-bounds heap write during log replay. The write is attacker-positioned and attacker-valued, and on a common embedded memory layout it reaches the FX_MEDIA driver callback, giving control of the instruction pointer.

Patch / fix

fixed in 1

Eclipse Foundation Eclipse ThreadX - FileX 6.5.2.202603

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 19 d ago (2026-10-20)

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.8	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

Eclipse Foundation Eclipse ThreadX - FileX

Classification

Weakness

CWE-787 Out-of-bounds Write
CWE-1284 Improper Validation of Specified Quantity in Input

References

github.com /eclipse-threadx/filex/security/advisories/GHSA-c8cj-fj9j-426v

Sources

CVE List CVE-2026-91041
NVD CVE-2026-91041

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary