CVE-2025-40759

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-08-12 · updated 2026-10-13
Weakness: CWE-502

Description

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 < V18 Update 6), 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 < V18 Update 6), 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.

Affected products

Siemens SIMATIC S7-PLCSIM V17: all versions
Siemens SIMATIC STEP 7 V17: before V17 Update 9 — fixed in V17 Update 9
Siemens SIMATIC STEP 7 V18: before V18 Update 6 — fixed in V18 Update 6
Siemens SIMATIC STEP 7 V19: before V19 Update 4 — fixed in V19 Update 4
Siemens SIMATIC STEP 7 V20: before V20 Update 4 — fixed in V20 Update 4
Siemens SIMATIC WinCC V17: before V17 Update 9 — fixed in V17 Update 9
Siemens SIMATIC WinCC V18: before V18 Update 6 — fixed in V18 Update 6
Siemens SIMATIC WinCC V19: before V19 Update 4 — fixed in V19 Update 4
Siemens SIMATIC WinCC V20: before V20 Update 4 — fixed in V20 Update 4
Siemens SIMOCODE ES V17: all versions
Siemens SIMOCODE ES V18: all versions
Siemens SIMOCODE ES V19: all versions
Siemens SIMOCODE ES V20: all versions
Siemens SIMOTION SCOUT TIA V5.4: all versions
Siemens SIMOTION SCOUT TIA V5.5: all versions
Siemens SIMOTION SCOUT TIA V5.6: before V5.6 SP1 HF7 — fixed in V5.6 SP1 HF7
Siemens SIMOTION SCOUT TIA V5.7: all versions
Siemens SINAMICS Startdrive V17: all versions
Siemens SINAMICS Startdrive V18: all versions
Siemens SINAMICS Startdrive V19: all versions
Siemens SINAMICS Startdrive V20: all versions
Siemens SIRIUS Safety ES V17 (TIA Portal): all versions
Siemens SIRIUS Safety ES V18 (TIA Portal): all versions
Siemens SIRIUS Safety ES V19 (TIA Portal): all versions
Siemens SIRIUS Safety ES V20 (TIA Portal): all versions
Siemens SIRIUS Soft Starter ES V17 (TIA Portal): all versions
Siemens SIRIUS Soft Starter ES V18 (TIA Portal): all versions
Siemens SIRIUS Soft Starter ES V19 (TIA Portal): all versions
Siemens SIRIUS Soft Starter ES V20 (TIA Portal): all versions
Siemens TIA Portal Cloud V17: all versions

How to fix

Upgrade to a fixed version: Siemens SIMATIC STEP 7 V17 V17 Update 9; Siemens SIMATIC STEP 7 V18 V18 Update 6; Siemens SIMATIC STEP 7 V19 V19 Update 4; Siemens SIMATIC STEP 7 V20 V20 Update 4; Siemens SIMATIC WinCC V17 V17 Update 9; Siemens SIMATIC WinCC V18 V18 Update 6; Siemens SIMATIC WinCC V19 V19 Update 4; Siemens SIMATIC WinCC V20 V20 Update 4; Siemens SIMOTION SCOUT TIA V5.6 V5.6 SP1 HF7; Siemens TIA Portal Cloud V19 V5.2.1.1; Siemens TIA Portal Cloud V20 V5.2.2.2. Check the vendor advisory for mitigations.

References

https://cert-portal.siemens.com/productcert/html/ssa-493396.html

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