CVE-2026-71256 json
nanoMODBUS Client-Side Out-of-Bounds Read Leading to Wild-Pointer Write via object_id
published 2026-08-05 3 mo ago modified 2026-10-24 15 d ago also EUVD-2026-53333
- cvss
- 9.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 46%
- public exploits
- 0
- none known
Summary
nanoMODBUS through v1.23.0 contains an out-of-bounds stack read leading to a wild-pointer write in nmbs_read_device_identification_basic / recv_read_device_identification_res in nanomodbus.c. A fixed 3-element stack array order[3] = {0,1,2} maps object IDs to buffer indices. The server-supplied object_id field (0-255, read directly from the wire) is used without any bounds check as buf_index = order[object_id].
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
- Assessed
- 3 mo ago
Exploit prediction
0.55% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected products
- debevv nanoMODBUS
Classification
- Weakness
-
- CWE-125 Out-of-bounds Read
References
-
github.com
/debevv/nanoMODBUS
third-party-advisory
-
github.com
/debevv/nanoMODBUS/blob/master/nanomodbus.c
third-party-advisory
Sources
- CVE List CVE-2026-71256
- NVD CVE-2026-71256
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.