CVE-2026-9653

HIGH

1756-EN2, 1756-EN3, and 1756-ENBT - Denial of Service via CIP Connection ID

Title source: cna

Description

A denial-of-service security issue exists across all the 1756-EN2, EN3, and ENBT communication module due to improper validation of CIP Implicit Connection packets. An attacker on the network can exploit this by sending crafted packets to continuously disrupt device connections, though device connections will recover immediately after.

References (1)

Core 1

Core References

https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1780.html

Scores

CVSS v4 8.7

EPSS 0.0018

EPSS Percentile 7.6%

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CISA SSVC

Vulnrichment

Exploitation none

Automatable yes

Technical Impact partial

Details

CWE

CWE-354

Status published

Products (2)

Rockwell Automation/1756-EN2, 1756-EN3 12.001 and before

Rockwell Automation/1756-ENBT 6.006

Published Jul 14, 2026

Tracked Since Jul 14, 2026