ICSA-26-015-04: Siemens SIMATIC and SIPLUS products
CISA advisory · released 2026-01-13
Source record Collected from CISA's CSAF advisory feed
- Distribution label in the document: TLP:WHITE
- Revision 6, 2026-07-02 (final)
CISA's summary
Summary: Siemens ET 200 devices contain a denial-of-service vulnerability that could be triggered by sending a valid S7 protocol Disconnect Request (COTP DR TPDU), causing the device to become unresponsive and require a power cycle to recover. Siemens has released new versions for several affected products and recommends to update to the latest versions. Siemens is preparing further fix versions and recommends specific countermeasures for products where fixes are not, or not yet available.
Products, as the advisory lists them
| Vendor | Product | Version |
|---|---|---|
| Siemens | SIMATIC ET 200AL IM 157-1 PN (6ES7157-1AB00-0AB0) | vers:all/* |
| Siemens | SIMATIC ET 200MP IM 155-5 PN HF (6ES7155-5AA00-0AC0) | vers:intdot/>=4.2.0 |
| Siemens | SIMATIC ET 200SP IM 155-6 MF HF (6ES7155-6MU00-0CN0) | vers:all/* |
| Siemens | SIMATIC ET 200SP IM 155-6 PN HA (incl. SIPLUS variants) | vers:intdot/<1.3 |
| Siemens | SIMATIC ET 200SP IM 155-6 PN R1 (6ES7155-6AU00-0HM0) | vers:intdot/<6.0.1 |
| Siemens | SIMATIC ET 200SP IM 155-6 PN/2 HF (6ES7155-6AU01-0CN0) | vers:intdot/>=4.2.0|<4.2.5 |
| Siemens | SIMATIC ET 200SP IM 155-6 PN/3 HF (6ES7155-6AU30-0CN0) | vers:intdot/<4.2.2 |
| Siemens | SIMATIC PN/MF Coupler (6ES7158-3MU10-0XA0) | vers:all/* |
| Siemens | SIMATIC PN/PN Coupler (6ES7158-3AD10-0XA0) | vers:intdot/<6.0.0 |
| Siemens | SIPLUS ET 200MP IM 155-5 PN HF (6AG1155-5AA00-2AC0) | vers:intdot/>=4.2.0 |
| Siemens | SIPLUS ET 200MP IM 155-5 PN HF (6AG1155-5AA00-7AC0) | vers:intdot/>=4.2.0 |
| Siemens | SIPLUS ET 200MP IM 155-5 PN HF T1 RAIL (6AG2155-5AA00-1AC0) | vers:intdot/>=4.2.0 |
| Siemens | SIPLUS ET 200SP IM 155-6 PN HF (6AG1155-6AU01-2CN0) | vers:intdot/>=4.2.0|<4.2.5 |
| Siemens | SIPLUS ET 200SP IM 155-6 PN HF (6AG1155-6AU01-7CN0) | vers:intdot/>=4.2.0|<4.2.5 |
| Siemens | SIPLUS ET 200SP IM 155-6 PN HF T1 RAIL (6AG2155-6AU01-1CN0) | vers:intdot/>=4.2.0|<4.2.5 |
| Siemens | SIPLUS ET 200SP IM 155-6 PN HF TX RAIL (6AG2155-6AU01-4CN0) | vers:intdot/>=4.2.0|<4.2.5 |
| Siemens | SIPLUS NET PN/PN Coupler (6AG2158-3AD10-4XA0) | vers:intdot/<6.0.0 |
DeSpy has not checked any unit, hardware revision or firmware.
Vulnerabilities in this advisory
- CVE-2025-40944 — CVE-2025-40944 · CWE-400
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.
Acknowledgments, as the advisory lists them
- Siemens ProductCERT: reported this vulnerability to CISA.
The advisory's legal notice
The use of Siemens Security Advisories is subject to the terms and conditions listed on: https://www.siemens.com/productcert/terms-of-use.
Sources
DeSpy's copy of this version is dated 2026-09-28.
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