Back to CVE records
Critical 9.8Published Aug 5, 2026

CVE-2026-71254nanoMODBUS Server-Side Out-of-Bounds Write in handle_read_file_record()

Updated under an hour ago ()

Does this affect you?

It affects debevv nanoMODBUS. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

nanoMODBUS through v1.23.0 contains an out-of-bounds write in the Modbus server-side handle_read_file_record function (FC 0x14, Read File Record) in nanomodbus.c. The function validates that the total request size does not exceed 245 bytes and that each sub-request's record_length is at most 124, but it never validates the CUMULATIVE response size across all sub-requests before processing them.

CVSS
9.8 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-787
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
TuranSec
NVD analysis
Deferred
Record last updated
Aug 10, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
debevv nanoMODBUS
debevv:nanomodbus (from the name)
through 1.23.0
CNA record

References

  • third-party-advisory
  • third-party-advisory

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

Your cookie choices
We use essential cookies to run this site, and, only with your consent, an advertising cookie from Google to measure whether our ads lead to sign-ups and subscriptions. See our for details.