CVE-2026-9653

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

Published Jul 14, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title 1756-EN2, 1756-EN3, and 1756-ENBT - Denial of Service via CIP Connection ID
Weaknesses CWE-354
References
Metrics cvssV4_0

{'score': 8.7, 'vector': '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'}

Subscriptions

No data.

Weaknesses

Sources

Status
PUBLISHED
Assigner
Rockwell
Published
Updated
Jul 14, 2026, 3:25 PM
Reserved
May 26, 2026, 8:07 PM
Status
Awaiting Analysis
Published
Jul 14, 2026, 3:17 PM
Modified
Jul 14, 2026, 4:46 PM