SIMATIC RCE via Type Confusion (CVE-2025-40759)
CVE-2025-40759 Published on August 12, 2025

A vulnerability has been identified in SIMATIC S7-PLCSIM V17 (All versions), SIMATIC STEP 7 V17 (All versions < V17 Update 9), SIMATIC STEP 7 V18 (All versions), SIMATIC STEP 7 V19 (All versions < V19 Update 4), SIMATIC STEP 7 V20 (All versions < V20 Update 4), SIMATIC WinCC V17 (All versions < V17 Update 9), SIMATIC WinCC V18 (All versions), SIMATIC WinCC V19 (All versions < V19 Update 4), SIMATIC WinCC V20 (All versions < V20 Update 4), SIMOCODE ES V17 (All versions), SIMOCODE ES V18 (All versions), SIMOCODE ES V19 (All versions), SIMOCODE ES V20 (All versions), SIMOTION SCOUT TIA V5.4 (All versions), SIMOTION SCOUT TIA V5.5 (All versions), SIMOTION SCOUT TIA V5.6 (All versions < V5.6 SP1 HF7), SIMOTION SCOUT TIA V5.7 (All versions), SINAMICS Startdrive V17 (All versions), SINAMICS Startdrive V18 (All versions), SINAMICS Startdrive V19 (All versions), SINAMICS Startdrive V20 (All versions), SIRIUS Safety ES V17 (TIA Portal) (All versions), SIRIUS Safety ES V18 (TIA Portal) (All versions), SIRIUS Safety ES V19 (TIA Portal) (All versions), SIRIUS Safety ES V20 (TIA Portal) (All versions), SIRIUS Soft Starter ES V17 (TIA Portal) (All versions), SIRIUS Soft Starter ES V18 (TIA Portal) (All versions), SIRIUS Soft Starter ES V19 (TIA Portal) (All versions), SIRIUS Soft Starter ES V20 (TIA Portal) (All versions), TIA Portal Cloud V17 (All versions), TIA Portal Cloud V18 (All versions), TIA Portal Cloud V19 (All versions < V5.2.1.1), TIA Portal Cloud V20 (All versions < V5.2.2.2). Affected products do not properly sanitize stored security properties when parsing project files. This could allow an attacker to cause a type confusion and execute arbitrary code within the affected application.

NVD

Weakness Type

What is a Marshaling, Unmarshaling Vulnerability?

The application deserializes untrusted data without sufficiently verifying that the resulting data will be valid.

CVE-2025-40759 has been classified to as a Marshaling, Unmarshaling vulnerability or weakness.

Products Associated with CVE-2025-40759

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2025-40759 are published in these products:

Siemens Simatic Step 7

Siemens Simatic Wincc

Affected Versions

Siemens SIMATIC S7-PLCSIM V17:

Before * is affected.

Siemens SIMATIC STEP 7 V17:

Before V17 Update 9 is affected.

Siemens SIMATIC STEP 7 V18:

Before * is affected.

Siemens SIMATIC STEP 7 V19:

Before V19 Update 4 is affected.

Siemens SIMATIC STEP 7 V20:

Before V20 Update 4 is affected.

Siemens SIMATIC WinCC V17:

Before V17 Update 9 is affected.

Siemens SIMATIC WinCC V18:

Before * is affected.

Siemens SIMATIC WinCC V19:

Before V19 Update 4 is affected.

Siemens SIMATIC WinCC V20:

Before V20 Update 4 is affected.

Siemens SIMOCODE ES V17:

Before * is affected.

Siemens SIMOCODE ES V18:

Before * is affected.

Siemens SIMOCODE ES V19:

Before * is affected.

Siemens SIMOCODE ES V20:

Before * is affected.

Siemens SIMOTION SCOUT TIA V5.4:

Before * is affected.

Siemens SIMOTION SCOUT TIA V5.5:

Before * is affected.

Siemens SIMOTION SCOUT TIA V5.6:

Before V5.6 SP1 HF7 is affected.

Siemens SIMOTION SCOUT TIA V5.7:

Before * is affected.

Siemens SINAMICS Startdrive V17:

Before * is affected.

Siemens SINAMICS Startdrive V18:

Before * is affected.

Siemens SINAMICS Startdrive V19:

Before * is affected.

Siemens SINAMICS Startdrive V20:

Before * is affected.

Siemens SIRIUS Safety ES V17 (TIA Portal):

Before * is affected.

Siemens SIRIUS Safety ES V18 (TIA Portal):

Before * is affected.

Siemens SIRIUS Safety ES V19 (TIA Portal):

Before * is affected.

Siemens SIRIUS Safety ES V20 (TIA Portal):

Before * is affected.

Siemens SIRIUS Soft Starter ES V17 (TIA Portal):

Before * is affected.

Siemens SIRIUS Soft Starter ES V18 (TIA Portal):

Before * is affected.

Siemens SIRIUS Soft Starter ES V19 (TIA Portal):

Before * is affected.

Siemens SIRIUS Soft Starter ES V20 (TIA Portal):

Before * is affected.

Siemens TIA Portal Cloud V17:

Before * is affected.

Siemens TIA Portal Cloud V18:

Before * is affected.

Siemens TIA Portal Cloud V19:

Before V5.2.1.1 is affected.

Siemens TIA Portal Cloud V20:

Before V5.2.2.2 is affected.

Exploit Probability

EPSS

0.13%

Percentile

32.22%