CVE-2025-40944

Published Jan 13, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed

Description

A vulnerability has been identified in SIMATIC ET 200AL IM 157-1 PN (6ES7157-1AB00-0AB0) (All versions), SIMATIC ET 200MP IM 155-5 PN HF (6ES7155-5AA00-0AC0) (All versions >= V4.2.0), SIMATIC ET 200SP IM 155-6 MF HF (6ES7155-6MU00-0CN0) (All versions), SIMATIC ET 200SP IM 155-6 PN HA (incl. SIPLUS variants) (All versions < V1.3), SIMATIC ET 200SP IM 155-6 PN R1 (6ES7155-6AU00-0HM0) (All versions < V6.0.1), SIMATIC ET 200SP IM 155-6 PN/2 HF (6ES7155-6AU01-0CN0) (All versions >= V4.2.0 < V4.2.5), SIMATIC ET 200SP IM 155-6 PN/3 HF (6ES7155-6AU30-0CN0) (All versions < V4.2.2), SIMATIC PN/MF Coupler (6ES7158-3MU10-0XA0) (All versions), SIMATIC PN/PN Coupler (6ES7158-3AD10-0XA0) (All versions < V6.0.0), SIPLUS ET 200MP IM 155-5 PN HF (6AG1155-5AA00-2AC0) (All versions >= V4.2.0), SIPLUS ET 200MP IM 155-5 PN HF (6AG1155-5AA00-7AC0) (All versions >= V4.2.0), SIPLUS ET 200MP IM 155-5 PN HF T1 RAIL (6AG2155-5AA00-1AC0) (All versions >= V4.2.0), SIPLUS ET 200SP IM 155-6 PN HF (6AG1155-6AU01-2CN0) (All versions >= V4.2.0 < V4.2.5), SIPLUS ET 200SP IM 155-6 PN HF (6AG1155-6AU01-7CN0) (All versions >= V4.2.0 < V4.2.5), SIPLUS ET 200SP IM 155-6 PN HF T1 RAIL (6AG2155-6AU01-1CN0) (All versions >= V4.2.0 < V4.2.5), SIPLUS ET 200SP IM 155-6 PN HF TX RAIL (6AG2155-6AU01-4CN0) (All versions >= V4.2.0 < V4.2.5), SIPLUS NET PN/PN Coupler (6AG2158-3AD10-4XA0) (All versions < V6.0.0). Affected devices do not properly handle S7 protocol session disconnect requests. When receiving a valid S7 protocol Disconnect Request (COTP DR TPDU) on TCP port 102, the devices enter an improper session state.

This could allow an attacker to cause the device to become unresponsive, leading to a denial-of-service condition that requires a power cycle to restore normal operation.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Siemens

SIMATIC ET 200AL IM 157-1 PN

unknown

Version	Status	Constraints
`0`	affected	< *

Siemens

SIMATIC ET 200MP IM 155-5 PN HF

unknown

Version	Status	Constraints
`V4.2.0`	affected	< *

Siemens

SIMATIC ET 200SP IM 155-6 MF HF

unknown

Version	Status	Constraints
`0`	affected	< *

Siemens

SIMATIC ET 200SP IM 155-6 PN HA (incl. SIPLUS variants)

unknown

Version	Status	Constraints
`0`	affected	< V1.3

Siemens

SIMATIC ET 200SP IM 155-6 PN R1

unknown

Version	Status	Constraints
`0`	affected	< V6.0.1

Siemens

SIMATIC ET 200SP IM 155-6 PN/2 HF

unknown

Version	Status	Constraints
`V4.2.0`	affected	< V4.2.5

Siemens

SIMATIC ET 200SP IM 155-6 PN/3 HF

unknown

Version	Status	Constraints
`0`	affected	< V4.2.2

Siemens

SIMATIC PN/MF Coupler

unknown

Version	Status	Constraints
`0`	affected	< *

Siemens

SIMATIC PN/PN Coupler

unknown

Version	Status	Constraints
`0`	affected	< V6.0.0

Siemens

SIPLUS ET 200MP IM 155-5 PN HF

unknown

Version	Status	Constraints
`V4.2.0`	affected	< *

Siemens

SIPLUS ET 200MP IM 155-5 PN HF

unknown

Version	Status	Constraints
`V4.2.0`	affected	< *

Siemens

SIPLUS ET 200MP IM 155-5 PN HF T1 RAIL

unknown

Version	Status	Constraints
`V4.2.0`	affected	< *

Siemens

SIPLUS ET 200SP IM 155-6 PN HF

unknown

Version	Status	Constraints
`V4.2.0`	affected	< V4.2.5

Siemens

SIPLUS ET 200SP IM 155-6 PN HF

unknown

Version	Status	Constraints
`V4.2.0`	affected	< V4.2.5

Siemens

SIPLUS ET 200SP IM 155-6 PN HF T1 RAIL

unknown

Version	Status	Constraints
`V4.2.0`	affected	< V4.2.5

Siemens

SIPLUS ET 200SP IM 155-6 PN HF TX RAIL

unknown

Version	Status	Constraints
`V4.2.0`	affected	< V4.2.5

Siemens

SIPLUS NET PN/PN Coupler

unknown

Version	Status	Constraints
`0`	affected	< V6.0.0

No data.

Vendor	Product	Versions
Siemens	Simatic Et 200al Im 157-1 Pn	—
Siemens	Simatic Et 200mp Im 155-5 Pn Hf	—
Siemens	Simatic Et 200sp Im 155-6 Mf Hf	—
Siemens	Simatic Et 200sp Im 155-6 Pn/2 Hf	—
Siemens	Simatic Et 200sp Im 155-6 Pn/3 Hf	—
Siemens	Simatic Et 200sp Im 155-6 Pn Ha	—
Siemens	Simatic Et 200sp Im 155-6 Pn R1	—
Siemens	Simatic Pn/mf Coupler	—
Siemens	Simatic Pn/pn Coupler	—
Siemens	Siplus Et 200mp Im 155-5 Pn Hf	—
Siemens	Siplus Et 200mp Im 155-5 Pn Hf T1 Rail	—
Siemens	Siplus Et 200sp Im 155-6 Pn Hf	—
Siemens	Siplus Et 200sp Im 155-6 Pn Hf T1 Rail	—
Siemens	Siplus Et 200sp Im 155-6 Pn Hf Tx Rail	—
Siemens	Siplus Net Pn/pn Coupler	—

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

No advisories available

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.436% probability within 30 days)

Exploitation none

Automatable yes

Technical Impact partial

References

Link	Providers
https://cert-portal.siemens.com/productcert/html/ssa-674753.html

History

Jun 9, 2026 10:15 AM Description updated View changes

Type	Values Removed	Values Added
Description	A vulnerability has been identified in SIMATIC ET 200AL IM 157-1 PN (6ES7157-1AB00-0AB0) (All versions), SIMATIC ET 200MP IM 155-5 PN HF (6ES7155-5AA00-0AC0) (All versions >= V4.2.0), SIMATIC ET 200SP IM 155-6 MF HF (6ES7155-6MU00-0CN0) (All versions), SIMATIC ET 200SP IM 155-6 PN HA (incl. SIPLUS variants) (All versions < V1.3), SIMATIC ET 200SP IM 155-6 PN R1 (6ES7155-6AU00-0HM0) (All versions < V6.0.1), SIMATIC ET 200SP IM 155-6 PN/2 HF (6ES7155-6AU01-0CN0) (All versions >= V4.2.0), SIMATIC ET 200SP IM 155-6 PN/3 HF (6ES7155-6AU30-0CN0) (All versions < V4.2.2), SIMATIC PN/MF Coupler (6ES7158-3MU10-0XA0) (All versions), SIMATIC PN/PN Coupler (6ES7158-3AD10-0XA0) (All versions < V6.0.0), SIPLUS ET 200MP IM 155-5 PN HF (6AG1155-5AA00-2AC0) (All versions >= V4.2.0), SIPLUS ET 200MP IM 155-5 PN HF (6AG1155-5AA00-7AC0) (All versions >= V4.2.0), SIPLUS ET 200MP IM 155-5 PN HF T1 RAIL (6AG2155-5AA00-1AC0) (All versions >= V4.2.0), SIPLUS ET 200SP IM 155-6 PN HF (6AG1155-6AU01-2CN0) (All versions >= V4.2.0), SIPLUS ET 200SP IM 155-6 PN HF (6AG1155-6AU01-7CN0) (All versions >= V4.2.0), SIPLUS ET 200SP IM 155-6 PN HF T1 RAIL (6AG2155-6AU01-1CN0) (All versions >= V4.2.0), SIPLUS ET 200SP IM 155-6 PN HF TX RAIL (6AG2155-6AU01-4CN0) (All versions >= V4.2.0), SIPLUS NET PN/PN Coupler (6AG2158-3AD10-4XA0) (All versions < V6.0.0). Affected devices do not properly handle S7 protocol session disconnect requests. When receiving a valid S7 protocol Disconnect Request (COTP DR TPDU) on TCP port 102, the devices enter an improper session state. This could allow an attacker to cause the device to become unresponsive, leading to a denial-of-service condition that requires a power cycle to restore normal operation.	A vulnerability has been identified in SIMATIC ET 200AL IM 157-1 PN (6ES7157-1AB00-0AB0) (All versions), SIMATIC ET 200MP IM 155-5 PN HF (6ES7155-5AA00-0AC0) (All versions >= V4.2.0), SIMATIC ET 200SP IM 155-6 MF HF (6ES7155-6MU00-0CN0) (All versions), SIMATIC ET 200SP IM 155-6 PN HA (incl. SIPLUS variants) (All versions < V1.3), SIMATIC ET 200SP IM 155-6 PN R1 (6ES7155-6AU00-0HM0) (All versions < V6.0.1), SIMATIC ET 200SP IM 155-6 PN/2 HF (6ES7155-6AU01-0CN0) (All versions >= V4.2.0 < V4.2.5), SIMATIC ET 200SP IM 155-6 PN/3 HF (6ES7155-6AU30-0CN0) (All versions < V4.2.2), SIMATIC PN/MF Coupler (6ES7158-3MU10-0XA0) (All versions), SIMATIC PN/PN Coupler (6ES7158-3AD10-0XA0) (All versions < V6.0.0), SIPLUS ET 200MP IM 155-5 PN HF (6AG1155-5AA00-2AC0) (All versions >= V4.2.0), SIPLUS ET 200MP IM 155-5 PN HF (6AG1155-5AA00-7AC0) (All versions >= V4.2.0), SIPLUS ET 200MP IM 155-5 PN HF T1 RAIL (6AG2155-5AA00-1AC0) (All versions >= V4.2.0), SIPLUS ET 200SP IM 155-6 PN HF (6AG1155-6AU01-2CN0) (All versions >= V4.2.0 < V4.2.5), SIPLUS ET 200SP IM 155-6 PN HF (6AG1155-6AU01-7CN0) (All versions >= V4.2.0 < V4.2.5), SIPLUS ET 200SP IM 155-6 PN HF T1 RAIL (6AG2155-6AU01-1CN0) (All versions >= V4.2.0 < V4.2.5), SIPLUS ET 200SP IM 155-6 PN HF TX RAIL (6AG2155-6AU01-4CN0) (All versions >= V4.2.0 < V4.2.5), SIPLUS NET PN/PN Coupler (6AG2158-3AD10-4XA0) (All versions < V6.0.0). Affected devices do not properly handle S7 protocol session disconnect requests. When receiving a valid S7 protocol Disconnect Request (COTP DR TPDU) on TCP port 102, the devices enter an improper session state. This could allow an attacker to cause the device to become unresponsive, leading to a denial-of-service condition that requires a power cycle to restore normal operation.

Jan 14, 2026 11:15 AM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Siemens Siemens simatic Et 200al Im 157-1 Pn Siemens simatic Et 200mp Im 155-5 Pn Hf Siemens simatic Et 200sp Im 155-6 Mf Hf Siemens simatic Et 200sp Im 155-6 Pn/2 Hf Siemens simatic Et 200sp Im 155-6 Pn/3 Hf Siemens simatic Et 200sp Im 155-6 Pn Ha Siemens simatic Et 200sp Im 155-6 Pn R1 Siemens simatic Pn/mf Coupler Siemens simatic Pn/pn Coupler Siemens siplus Et 200mp Im 155-5 Pn Hf Siemens siplus Et 200mp Im 155-5 Pn Hf T1 Rail Siemens siplus Et 200sp Im 155-6 Pn Hf Siemens siplus Et 200sp Im 155-6 Pn Hf T1 Rail Siemens siplus Et 200sp Im 155-6 Pn Hf Tx Rail Siemens siplus Net Pn/pn Coupler
Vendors & Products		Siemens Siemens simatic Et 200al Im 157-1 Pn Siemens simatic Et 200mp Im 155-5 Pn Hf Siemens simatic Et 200sp Im 155-6 Mf Hf Siemens simatic Et 200sp Im 155-6 Pn/2 Hf Siemens simatic Et 200sp Im 155-6 Pn/3 Hf Siemens simatic Et 200sp Im 155-6 Pn Ha Siemens simatic Et 200sp Im 155-6 Pn R1 Siemens simatic Pn/mf Coupler Siemens simatic Pn/pn Coupler Siemens siplus Et 200mp Im 155-5 Pn Hf Siemens siplus Et 200mp Im 155-5 Pn Hf T1 Rail Siemens siplus Et 200sp Im 155-6 Pn Hf Siemens siplus Et 200sp Im 155-6 Pn Hf T1 Rail Siemens siplus Et 200sp Im 155-6 Pn Hf Tx Rail Siemens siplus Net Pn/pn Coupler

Jan 13, 2026 6:15 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Jan 13, 2026 10:00 AM Description updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		A vulnerability has been identified in SIMATIC ET 200AL IM 157-1 PN (6ES7157-1AB00-0AB0) (All versions), SIMATIC ET 200MP IM 155-5 PN HF (6ES7155-5AA00-0AC0) (All versions >= V4.2.0), SIMATIC ET 200SP IM 155-6 MF HF (6ES7155-6MU00-0CN0) (All versions), SIMATIC ET 200SP IM 155-6 PN HA (incl. SIPLUS variants) (All versions < V1.3), SIMATIC ET 200SP IM 155-6 PN R1 (6ES7155-6AU00-0HM0) (All versions < V6.0.1), SIMATIC ET 200SP IM 155-6 PN/2 HF (6ES7155-6AU01-0CN0) (All versions >= V4.2.0), SIMATIC ET 200SP IM 155-6 PN/3 HF (6ES7155-6AU30-0CN0) (All versions < V4.2.2), SIMATIC PN/MF Coupler (6ES7158-3MU10-0XA0) (All versions), SIMATIC PN/PN Coupler (6ES7158-3AD10-0XA0) (All versions < V6.0.0), SIPLUS ET 200MP IM 155-5 PN HF (6AG1155-5AA00-2AC0) (All versions >= V4.2.0), SIPLUS ET 200MP IM 155-5 PN HF (6AG1155-5AA00-7AC0) (All versions >= V4.2.0), SIPLUS ET 200MP IM 155-5 PN HF T1 RAIL (6AG2155-5AA00-1AC0) (All versions >= V4.2.0), SIPLUS ET 200SP IM 155-6 PN HF (6AG1155-6AU01-2CN0) (All versions >= V4.2.0), SIPLUS ET 200SP IM 155-6 PN HF (6AG1155-6AU01-7CN0) (All versions >= V4.2.0), SIPLUS ET 200SP IM 155-6 PN HF T1 RAIL (6AG2155-6AU01-1CN0) (All versions >= V4.2.0), SIPLUS ET 200SP IM 155-6 PN HF TX RAIL (6AG2155-6AU01-4CN0) (All versions >= V4.2.0), SIPLUS NET PN/PN Coupler (6AG2158-3AD10-4XA0) (All versions < V6.0.0). Affected devices do not properly handle S7 protocol session disconnect requests. When receiving a valid S7 protocol Disconnect Request (COTP DR TPDU) on TCP port 102, the devices enter an improper session state. This could allow an attacker to cause the device to become unresponsive, leading to a denial-of-service condition that requires a power cycle to restore normal operation.
Weaknesses		CWE-400
References		https://cert-portal.siemens.com/productcert/html/ssa-674753.html
Metrics		cvssV3_1 `{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}` cvssV4_0 `{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}`

Subscriptions

Siemens Simatic Et 200al Im 157-1 Pn Simatic Et 200mp Im 155-5 Pn Hf Simatic Et 200sp Im 155-6 Mf Hf Simatic Et 200sp Im 155-6 Pn/2 Hf Simatic Et 200sp Im 155-6 Pn/3 Hf Simatic Et 200sp Im 155-6 Pn Ha Simatic Et 200sp Im 155-6 Pn R1 Simatic Pn/mf Coupler Simatic Pn/pn Coupler Siplus Et 200mp Im 155-5 Pn Hf Siplus Et 200mp Im 155-5 Pn Hf T1 Rail Siplus Et 200sp Im 155-6 Pn Hf Siplus Et 200sp Im 155-6 Pn Hf T1 Rail Siplus Et 200sp Im 155-6 Pn Hf Tx Rail Siplus Net Pn/pn Coupler

Weaknesses