In Omron PLC CJ series, all versions, and Omron PLC CS series, all versions, an attacker could monitor traffic between the PLC and the cont…

published 2019-12-16 6 y ago modified 2026-06-17 4 mo ago also EUVD-2019-4988

cvss: 8.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.9%; EPSS 0.9% chance of exploitation in 30 days, percentile 59%
public exploits: 0; none known

In Omron PLC CJ series, all versions, and Omron PLC CS series, all versions, an attacker could monitor traffic between the PLC and the controller and replay requests that could result in the opening and closing of industrial valves.

Vendor advisories

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

cisa ICSA-19-346-02 updated 2019-12-12 cvss 8.1

Omron PLC CJ and CS Series

Omron PLC CJ series Omron PLC CS series Omron PLC NX1P2 series
affected: mitigation “Filter FINS port: Protect access to Omron's PLC with a firewall and blocking unnecessary remote access to FINS port (default: 9600).” gcc01.safelinks.protection.outlook.com

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: no
Technical impact: partial
Assessed: 5 mo ago (2026-06-02)

Exploit prediction

0.87% chance of exploitation in the next 30 days, higher than 59% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	8.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:H
NVD	3.1	8.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:H
CNA	3.1	8.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:H
NVD	2.0	6.8	AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

n/a Omron PLC CJ and CS Series

Classification

Weakness

CWE-294 Authentication Bypass by Capture-replay

References

us-cert.gov /ics/advisories/icsa-19-346-02
third-party-advisory, us-government-resource

Sources

CVE List CVE-2019-13533
NVD CVE-2019-13533

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.

Summary