Buffer overflow in Eclipse Threadx Usbx
CVE-2025-55095
The function _ux_host_class_storage_media_mount() is responsible for mounting partitions on a USB mass storage device. When it encounters an extended partition entry in the partition table, it recursively calls itself to mount the next logical partition. This recursion occurs in _ux_host_class_storage_partition_read(), which parses up to four partition entries. If an extended partition is found (with type UX_HOST_CLASS_STORAGE_PARTITION_EXTENDED or EXTENDED_LBA_MAPPED), the code invokes: _ux_host_class_storage_media_mount(storage, sector + _ux_utility_long_get(...)); There is no limit on the recursion depth or tracking of visited sectors. As a result, a malicious or malformed disk image can include cyclic or excessively deep chains of extended partitions, causing the function to recurse until stack overflow occurs.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.002 (5.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 5th percentile — 5.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000
Affected products
Weakness classification (CWE)
References
- github.com/eclipse-threadx/usbx/security/advisories/GHSA-qfmp-wch9-rpv2 (Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2025-55095?
- CVE-2025-55095 is a medium-severity vulnerability in Eclipse Threadx Usbx, classified under Stack-based Buffer Overflow. CVSS score: 4.2/10. Published 2026-01-27.
- How severe is CVE-2025-55095?
- Medium severity. CVSS v3 base score is 4.2 out of 10.