CVE-2026-44104Network attack vector

Firmware compromise via CRC32-only update validation

Published Jul 30, 2026 · Updated Jul 30, 2026

Improper firmware verification in Phoenix Contact CHARX SEC-3xxx before 1.9.1 allows remote attackers to install modified firmware. CharxControllerAgent accepts a basemodule update after checking only its CRC32 checksum and does not authenticate the image with a cryptographic signature. No authentication is required, and a crafted image can replace trusted firmware and compromise the controller; arbitrary-code execution is reported when the flaw is chained with other vulnerabilities.

CVSS severity9.3
Critical
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper firmware verification in Phoenix Contact CHARX SEC-3xxx before 1.9.1 allows remote attackers to install modified firmware. CharxControllerAgent accepts a basemodule update after checking only its CRC32 checksum and does not authenticate the image with a cryptographic signature. No authentication is required, and a crafted image can replace trusted firmware and compromise the controller; arbitrary-code execution is reported when the flaw is chained with other vulnerabilities.

The record

CVE
CVE-2026-44104
Published
Jul 30, 2026
Updated
Jul 30, 2026
Vendor
Phoenix Contact
Product
CHARX SEC-3100
Classifications
CWE-347, T1495
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 30, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 30, 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=1.0.0 <1.9.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Phoenix Contact · CHARX SEC-3100version=1.0.0 <1.9.1
Phoenix Contact · CHARX SEC-3150version=1.0.0 <1.9.1
Phoenix Contact · CHARX SEC-3050version=1.0.0 <1.9.1
Phoenix Contact · CHARX SEC-3000version=1.0.0 <1.9.1

Published CVSS scores

9.8CERT VDECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3CERT VDECVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-347Improper Verification of Cryptographic Signature
T1495Firmware Corruption

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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