CVE-2025-40759

Code execution via unsanitized project security properties

Published Aug 12, 2025 · Updated Dec 9, 2025

Deserialization in Siemens engineering platforms allows local users to execute arbitrary code by opening a crafted project file. The applications fail to sanitize stored security properties before reconstructing them, allowing attacker-controlled data to trigger type confusion. Exploitation requires a user to open an untrusted project, and the resulting code runs within the affected application's security context.

CVSS severity8.5
High
EPSS probability0.18%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deserialization in Siemens engineering platforms allows local users to execute arbitrary code by opening a crafted project file. The applications fail to sanitize stored security properties before reconstructing them, allowing attacker-controlled data to trigger type confusion. Exploitation requires a user to open an untrusted project, and the resulting code runs within the affected application's security context.

The record

CVE
CVE-2025-40759
Published
Aug 12, 2025
Updated
Dec 9, 2025
Vendor
Siemens
Product
SIMATIC STEP 7
Classifications
CWE-502, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 12, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 9, 2025Record 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 <*
  2. Affected versionversion=0 <V17 Update 9
  3. Affected versionversion=0 <V19 Update 4
  4. Affected versionversion=0 <V20 Update 4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Siemens · SIMATIC STEP 7version=0 <*; version=0 <V17 Update 9; version=0 <V19 Update 4; version=0 <V20 Update 4
Siemens · SIRIUS Safety ES (TIA Portal)version=0 <*
Siemens · TIA Portal Cloudversion=0 <*; version=0 <V5.2.1.1; version=0 <V5.2.2.2
Siemens · SIMOCODE ESversion=0 <*
Siemens · SIMATIC WinCC (TIA Portal)version=0 <*; version=0 <V17 Update 9; version=0 <V19 Update 4; version=0 <V20 Update 4
Siemens · SIMATIC S7-PLCSIMversion=0 <*
Siemens · SIMOTION SCOUT TIAversion=0 <*; version=0 <V5.6 SP1 HF7
Siemens · SINAMICS Startdriveversion=0 <*
Siemens · SIRIUS Soft Starter ES (TIA Portal)version=0 <*

Published CVSS scores

8.5Siemens ProductCERTCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
7.8Siemens ProductCERTCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1204.002User Execution: Malicious File

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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