CVE-2026-86326Network attack vector

Persistent code execution via unverified firmware images

Published Oct 2, 2026 · Updated Oct 2, 2026

Improper firmware signature verification in Moxa MGate MB3170 and MB3270 Series 1.0 allows attackers to install modified firmware. The firmware update path accepts an image without adequately verifying its cryptographic authenticity; the precise verification failure has not been publicly described. Exploitation requires high privileges and access to the update interface, after which unauthorized code can persist across firmware updates and disrupt the gateway.

CVSS severityUnavailable
Unscored
EPSS probability0.19%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper firmware signature verification in Moxa MGate MB3170 and MB3270 Series 1.0 allows attackers to install modified firmware. The firmware update path accepts an image without adequately verifying its cryptographic authenticity; the precise verification failure has not been publicly described. Exploitation requires high privileges and access to the update interface, after which unauthorized code can persist across firmware updates and disrupt the gateway.

The record

CVE
CVE-2026-86326
Published
Oct 2, 2026
Updated
Oct 2, 2026
Vendor
Moxa
Product
MGate MB3270 Series
Classifications
T1601.001
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Oct 2, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 2, 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=1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Moxa · MGate MB3270 Seriesversion=1.0
Moxa · MGate MB3170 Seriesversion=1.0

Published CVSS scores

No CVSS assessment is available in this record.

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1601.001Patch System Image

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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