CVE-2026-71263

critical · 9.1

The LINUXTCP port of FreeModbus contains an off-by-one bounds check in xMBPortTCPPool (demo/LINUXTCP/port/porttcp.c). The check uses a strict greater-than comparison instead of greater-than-or-equal against the 263-byte MB_TCP_BUF_SIZE limit.

9.1

CVSS

0.3%

EPSS (exploit prob.)

21st

EPSS percentile

2026-08-05

Published

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

Weaknesses

CWE-787

References

https://github.com/cwalter-at/freemodbus
https://github.com/cwalter-at/freemodbus/blob/master/demo/LINUXTCP/port/porttcp.c

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-71263