CVE-2025-40795Network attack vector

Unauthenticated code execution via message 17 overflow

Published Sep 9, 2025 · Updated Jun 9, 2026

Stack overflow in Siemens UMC before 2.15.1.3 and PCS neo 4.1, 5.0, and 6.0 before SP1 Update 1 allows remote attackers to execute code. The um.Ris.exe service mishandles a crafted type 17 network message and overruns a stack buffer. A crafted unauthenticated request can also interrupt the service; no user interaction or prior access is required.

CVSS severity9.3
Critical
EPSS probability0.70%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack overflow in Siemens UMC before 2.15.1.3 and PCS neo 4.1, 5.0, and 6.0 before SP1 Update 1 allows remote attackers to execute code. The um.Ris.exe service mishandles a crafted type 17 network message and overruns a stack buffer. A crafted unauthenticated request can also interrupt the service; no user interaction or prior access is required.

The record

CVE
CVE-2025-40795
Published
Sep 9, 2025
Updated
Jun 9, 2026
Vendor
Siemens
Product
User Management Component (UMC)
Classifications
CWE-121, T0866
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 9, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 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 <V2.15.1.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Siemens · User Management Component (UMC)version=0 <V2.15.1.3
Siemens · SIMATIC PCS neoversion=0 <*; version=0 <V6.0 SP1 Update 1

Published CVSS scores

9.8Siemens ProductCERTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3Siemens ProductCERTCVSS: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 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-121Stack-based Buffer Overflow
T0866Exploitation of Remote Services

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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