TCP Connection Exhaustion Vulnerability in CODESYS EtherNet/IP Adapter by CODESYS
CVE-2026-35225

8.7HIGH

Key Information:

Vendor

Codesys

Status
Codesys Ethernetip
Vendor
CVE Published:
23 April 2026

What is CVE-2026-35225?

An unauthenticated remote attacker can exploit a vulnerability in the CODESYS EtherNet/IP adapter, overwhelming the TCP connection capacity. This denial-of-service (DoS) attack renders legitimate clients unable to establish new connections, thereby disrupting critical communication within systems utilizing the CODESYS environment. Organizations using the affected products are advised to implement protective measures to safeguard against this type of attack.

Affected Version(s)

CODESYS EtherNetIP 1.0.0.0 < 4.9.0.0

References

https://codesys.csaf-tp.certvde.com/.well-known/csaf/whit...
vendor-advisory
https://www.certvde.com/en/advisories/VDE-2026-040/
vendor-advisory

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

ABB
.