CVE-2026-71263

Impact

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.

Affected packages

This record carries no package version data, so it cannot be matched against a dependency list automatically. Read the advisory and compare your version by hand.

Weakness classification

References

• NVD record
• CVE.org record
• https://github.com/cwalter-at/freemodbus
• https://github.com/cwalter-at/freemodbus/blob/master/demo/LINUXTCP/port/porttcp.c