CVE-2026-40852Network attack vector

Authenticated command execution via stored configuration injection

Published May 27, 2026 · Updated May 27, 2026

OS command injection in affected REX and mbNET firmware allows remote authenticated users to execute commands through malicious configuration values. The configuration generator stores attacker-controlled values and passes them to a system execution operation without validating or neutralizing command syntax. High-privilege configuration access is required, and the payload executes when a later configuration is generated, enabling full device compromise.

CVSS severity7.2
High
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in affected REX and mbNET firmware allows remote authenticated users to execute commands through malicious configuration values. The configuration generator stores attacker-controlled values and passes them to a system execution operation without validating or neutralizing command syntax. High-privilege configuration access is required, and the payload executes when a later configuration is generated, enabling full device compromise.

The record

CVE
CVE-2026-40852
Published
May 27, 2026
Updated
May 27, 2026
Vendor
Helmholz GmbH & Co. KG
Product
REX 200/250
Classifications
CWE-78, T1059
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=0.0.0 <=8.4.4
  2. Affected versionversion=8.4.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Helmholz GmbH & Co. KG · REX 200/250version=0.0.0 <=8.4.4; version=8.4.4
Helmholz GmbH & Co. KG · REX 100version=0.0.0 <=3.0.2; version=3.0.2
MB connect line · mbNET.miniversion=0.0.0 <=3.0.2; version=3.0.2

Published CVSS scores

7.2MB connect lineCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059Command and Scripting Interpreter

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

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Your stack

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