CVE-2026-35227: Improper resource management in CODESYS Modbus TCP Server

Published May 12, 2026

Updated

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.

Affected Software

1 affected component

CODESYS CODESYS Modbus TCP Server

Event History

May 12, 2026

CVE Published

via MITRE·07:14 AM

Data Sourced

via MITRE·07:14 AM

DescriptionWeakness

Data Sourced

via NVD·08:16 AM

DescriptionSeverityWeakness

Frequently Asked Questions

What is the severity of CVE-2026-35227?

CVE-2026-35227 is classified as a high severity vulnerability due to its impact on the availability of the CODESYS Modbus TCP Server.

How do I fix CVE-2026-35227?

To mitigate CVE-2026-35227, update the CODESYS Modbus TCP Server to the latest version provided by the vendor.

What causes CVE-2026-35227?

CVE-2026-35227 is caused by improper resource management which leads to a race condition in TCP connection handling.

Can CVE-2026-35227 be exploited remotely?

Yes, CVE-2026-35227 can be exploited by unauthenticated remote attackers.

What is the potential impact of CVE-2026-35227?

The potential impact of CVE-2026-35227 is that it may exhaust all available TCP connections, preventing legitimate clients from connecting.