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Fencer Vulns
high 7.5

CVE-2025-40944 json

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 (6…

published 2026-01-13 9 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-2359

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits
0
none known

Summary

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.

Patch / fix

  • Siemens SIMATIC ET 200SP IM 155-6 PN HA (incl. SIPLUS variants) V1.3
  • Siemens SIMATIC ET 200SP IM 155-6 PN R1 V6.0.1
  • Siemens SIMATIC ET 200SP IM 155-6 PN/2 HF V4.2.5
  • Siemens SIMATIC ET 200SP IM 155-6 PN/3 HF V4.2.2
  • Siemens SIMATIC PN/PN Coupler V6.0.0
  • Siemens SIPLUS ET 200SP IM 155-6 PN HF V4.2.5
  • Siemens SIPLUS ET 200SP IM 155-6 PN HF T1 RAIL V4.2.5
  • Siemens SIPLUS ET 200SP IM 155-6 PN HF TX RAIL V4.2.5
  • Siemens SIPLUS NET PN/PN Coupler V6.0.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-26-015-04 updated cvss 7.5

Siemens SIMATIC and SIPLUS products

  • Siemens SIMATIC ET 200AL IM 157-1 PN (6ES7157-1AB00-0AB0) Siemens SIMATIC ET 200MP IM 155-5 PN HF (6ES7155-5AA00-0AC0) >= 4.2.0 Siemens SIMATIC ET 200SP IM 155-6 MF HF (6ES7155-6MU00-0CN0)
    affected: mitigation, no fix planned
  • Siemens SIMATIC ET 200SP IM 155-6 PN HA (incl. SIPLUS variants) < 1.3
    affected: fixed in V1.3, mitigation support.industry.siemens.com
  • Siemens SIMATIC ET 200SP IM 155-6 PN R1 (6ES7155-6AU00-0HM0) < 6.0.1
    affected: fixed in V6.0.1, mitigation support.industry.siemens.com
  • Siemens SIMATIC ET 200SP IM 155-6 PN/2 HF (6ES7155-6AU01-0CN0) >= 4.2.0, < 4.2.5
    affected: fixed in V4.2.5, mitigation support.industry.siemens.com
  • Siemens SIMATIC ET 200SP IM 155-6 PN/3 HF (6ES7155-6AU30-0CN0) < 4.2.2
    affected: fixed in V4.2.2, mitigation support.industry.siemens.com
  • Siemens SIMATIC PN/MF Coupler (6ES7158-3MU10-0XA0)
    affected: mitigation, no fix planned
  • Siemens SIMATIC PN/PN Coupler (6ES7158-3AD10-0XA0) < 6.0.0
    affected: fixed in V6.0.0, mitigation support.industry.siemens.com
  • Siemens SIPLUS ET 200MP IM 155-5 PN HF (6AG1155-5AA00-2AC0) >= 4.2.0 Siemens SIPLUS ET 200MP IM 155-5 PN HF (6AG1155-5AA00-7AC0) >= 4.2.0 Siemens SIPLUS ET 200MP IM 155-5 PN HF T1 RAIL (6AG2155-5AA00-1AC0) >= 4.2.0
    affected: mitigation, no fix planned
show 2 more
  • Siemens SIPLUS ET 200SP IM 155-6 PN HF (6AG1155-6AU01-2CN0) >= 4.2.0, < 4.2.5 Siemens SIPLUS ET 200SP IM 155-6 PN HF (6AG1155-6AU01-7CN0) >= 4.2.0, < 4.2.5 Siemens SIPLUS ET 200SP IM 155-6 PN HF T1 RAIL (6AG2155-6AU01-1CN0) >= 4.2.0, < 4.2.5 Siemens SIPLUS ET 200SP IM 155-6 PN HF TX RAIL (6AG2155-6AU01-4CN0) >= 4.2.0, < 4.2.5
    affected: fixed in V4.2.5, mitigation support.industry.siemens.com
  • Siemens SIPLUS NET PN/PN Coupler (6AG2158-3AD10-4XA0) < 6.0.0
    affected: fixed in V6.0.0, mitigation support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
9 mo ago

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 4.0 8.7 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
CNA 4.0 8.7 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • 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 HA (incl. SIPLUS variants)
  • Siemens SIMATIC ET 200SP IM 155-6 PN R1
  • Siemens SIMATIC ET 200SP IM 155-6 PN/2 HF
  • Siemens SIMATIC ET 200SP IM 155-6 PN/3 HF
  • 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

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.