CVE-2026-71254

critical · 9.8

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.

9.8

CVSS

0.3%

EPSS (exploit prob.)

24th

EPSS percentile

2026-08-05

Published

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weaknesses

CWE-787

References

https://github.com/debevv/nanoMODBUS
https://github.com/debevv/nanoMODBUS/blob/master/nanomodbus.c

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-71254