CVE-2026-4436Network attack vector

Gas odorization manipulation via unauthenticated Modbus writes

Published Apr 9, 2026 · Updated Apr 9, 2026

Missing authentication in GPL Odorizers GPL 750 controllers allows remote attackers to alter odorant injection through Modbus packets. The Modbus interface accepts unauthenticated writes to registers consumed by the odorant-injection logic instead of verifying the sender's authority. Network reachability to the controller is sufficient to cause too much or too little odorant to enter a gas line; no user interaction is required.

CVSS severity8.6
High
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authentication in GPL Odorizers GPL 750 controllers allows remote attackers to alter odorant injection through Modbus packets. The Modbus interface accepts unauthenticated writes to registers consumed by the odorant-injection logic instead of verifying the sender's authority. Network reachability to the controller is sufficient to cause too much or too little odorant to enter a gas line; no user interaction is required.

The record

CVE
CVE-2026-4436
Published
Apr 9, 2026
Updated
Apr 9, 2026
Vendor
GPL Odorizers
Product
GPL 750
Classifications
CWE-306, T0836
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 9, 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=v1.0 <v6.0
  2. Affected versionversion=v13.0 <v20.0
  3. Affected versionversion=v18.4 <v20.0
  4. Affected versionversion=v4.0 <v6.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

GPL Odorizers · GPL 750version=v1.0 <v6.0; version=v13.0 <v20.0; version=v18.4 <v20.0; version=v4.0 <v6.0

Published CVSS scores

8.6ICS-CERTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A: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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
T0836Modify Parameter

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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