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Fencer Vulns
high 8.7

CVE-2026-9653 json

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

published 2026-07-14 3 mo ago modified 2026-07-14 3 mo ago also EUVD-2026-43695

cvss
8.7
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 14%
public exploits
0
none known

Summary

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.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-26-197-02 updated cvss 7.5

Rockwell Automation 1756-EN2, 1756-EN3, and 1756-ENBT

  • Rockwell Automation 1756-EN2 <=V12.001 Rockwell Automation 1756-EN3 <=V12.001
    affected: fixed in V12.002
  • Rockwell Automation 1756-ENBT V6.006
    affected: vendor fix

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 14% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 8.7 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
CNA 4.0 8.7 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

Affected products

  • Rockwell Automation 1756-EN2, 1756-EN3
  • Rockwell Automation 1756-ENBT

Classification

Weakness
  • CWE-354 Improper Validation of Integrity Check Value

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.