PT-2026-39943 · Codesys · Codesys Modbus

Published 2026-05-12 · Updated 2026-05-12 · CVE-2026-35227

Mitre

CVSS v4.0

8.2

High

Base vector

AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

An unauthenticated remote attacker may exhaust all available TCP connections in the CODESYS Modbus TCP Server stack if a race condition in connection handling is successfully exploited, preventing legitimate clients from establishing new connections.

Fix

Missing Release of Resource after Effective Lifetime

Weakness Enumeration

CWE-772

Related Identifiers

CVE-2026-35227

Affected Products

Codesys Modbus

References · 2

• https://nvd.nist.gov/vuln/detail/CVE-2026-35227 · Security Note
• https://certvde.com/de/advisories/VDE-2026-042 · Note