CVE-2026-35226

PLC application stop via malformed PROFINET data

Published Jul 29, 2026 · Updated Jul 29, 2026

Out-of-bounds write in CODESYS PROFINET Controller allows remote attackers on the same network segment to stop a PLC application. The downloaded protocol stack writes beyond a buffer while processing invalid PROFINET communication data, and the runtime handles the resulting exception. Only projects with a configured PROFINET Controller are exposed; exploitation causes a controlled stop until restart, while code execution is not feasible.

CVSS severity7.1
High
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Out-of-bounds write in CODESYS PROFINET Controller allows remote attackers on the same network segment to stop a PLC application. The downloaded protocol stack writes beyond a buffer while processing invalid PROFINET communication data, and the runtime handles the resulting exception. Only projects with a configured PROFINET Controller are exposed; exploitation causes a controlled stop until restart, while code execution is not feasible.

The record

CVE
CVE-2026-35226
Published
Jul 29, 2026
Updated
Jul 29, 2026
Vendor
CODESYS GmbH
Product
CODESYS PROFINET Controller SL
Classifications
CWE-787, T0814
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.4.0.0 <4.8.0.0

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

CODESYS GmbH · CODESYS PROFINET Controller SLversion=4.4.0.0 <4.8.0.0

Published CVSS scores

6.5CERT@VDECVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.1CERT@VDECVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T0814Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo