CVE-2026-35227 PUBLISHED

Improper resource management in CODESYS Modbus TCP Server

Assigner: CERTVDE
Reserved: 01.04.2026 Published: 12.05.2026 Updated: 12.05.2026

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.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS Score: 8.2

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	Present	Availability	High	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	CODESYS
Product	CODESYS Modbus
Versions	Default: unaffected affected from 1.0.0.0 to 4.6.0.0 (excl.)

Credits

ABB Schweiz AG finder

References

https://certvde.com/de/advisories/VDE-2026-042

Problem Types

CWE-772 Missing Release of Resource after Effective Lifetime CWE