CVE-2026-78012: Stack-based Buffer Overflow in Pyramid Solutions NetStaX EtherNet/IP Stack

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-01 · updated 2026-09-08
Weakness: CWE-121

Description

An issue in the NetStaX EtherNet/IP Stack prior to v5.6.1 could allow a large Class 3 explicit-message request to exceed the application-side receive buffer without generating an error or warning. The result could be memory corruption, a device crash, or a potential remote attack vector without the originating device receiving a CIP error indicating that the request could not be processed.

Affected products

Pyramid Solutions EtherNet/IP Adapter Development Kit (EADK): through v5.6.1
Pyramid Solutions EtherNet/IP Adapter Development Kit with CIP Security (EADK-SECURE): through v5.6.1
Pyramid Solutions EtherNet/IP Adapter DLL Kit (EIPA): through v5.6.1
Pyramid Solutions EtherNet/IP Adapter DLL Kit with CIP Security (EIPA-SECURE): through v5.6.1
Pyramid Solutions EtherNet/IP Scanner Development Kit (ESDK): through v5.6.1
Pyramid Solutions EtherNet/IP Scanner Development Kit with CIP Security (ESDK-SECURE): before v5.6.1 — fixed in v5.6.1
Pyramid Solutions EtherNet/IP Scanner DLL Kit (EIPS): through v5.6.1
Pyramid Solutions EtherNet/IP Scanner DLL Kit with CIP Security (EIPS-SECURE): through v5.6.1

How to fix

Upgrade to a fixed version: Pyramid Solutions EtherNet/IP Scanner Development Kit with CIP Security (ESDK-SECURE) v5.6.1. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-78012 or the next vulnerability affects your stack