CVE-2026-54800Network attack vector

Unauthorized OPC UA control via disabled security

Published Jul 9, 2026 · Updated Jul 9, 2026

Insecure defaults in Siemens CPCI85 before 26.20 and SICORE before 26.20.0 allow remote attackers to access and control OPC UA functions. The shipped OPC UA configuration disables every security mechanism, exposing endpoints without message protection or enforced authentication. Network reachability to the OPC UA server is sufficient; successful access exposes information and permits control over critical functions without affecting availability.

CVSS severity6.3
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insecure defaults in Siemens CPCI85 before 26.20 and SICORE before 26.20.0 allow remote attackers to access and control OPC UA functions. The shipped OPC UA configuration disables every security mechanism, exposing endpoints without message protection or enforced authentication. Network reachability to the OPC UA server is sufficient; successful access exposes information and permits control over critical functions without affecting availability.

The record

CVE
CVE-2026-54800
Published
Jul 9, 2026
Updated
Jul 9, 2026
Vendor
Siemens
Product
SICORE Base system
Classifications
CWE-1188, T0831
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 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=0 <V26.20.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Siemens · SICORE Base systemversion=0 <V26.20.0
Siemens · CPCI85 Central Processing/Communicationversion=0 <V26.20

Published CVSS scores

6.3SiemensCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
4.8SiemensCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/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 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-1188Initialization of a Resource with an Insecure Default
T0831Manipulation of Control

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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