A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1).

published 2025-12-09 11 mo ago modified 2026-10-23 16 d ago also EUVD-2025-201917

cvss: 4.6; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 11%
public exploits: 0; none known

A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1). The affected device contains a USB port which allows unauthenticated connections. This could allow an attacker with physical access to the device to trigger reboot that could cause denial of service condition.

Patch / fix

fixed in 1

Siemens SIMATIC CN 4100 V4.0.1

Vendor advisories

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

cisa ICSA-26-015-12 updated 2025-12-09 cvss 4.6

Siemens SIMATIC CN 4100

Siemens SIMATIC CN 4100 < 4.0.1
affected: fixed in V4.0.1 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: no
Technical impact: partial
Assessed: 10 mo ago (2025-12-09)

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	4.6	CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA	4.0	5.1	CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CNA	4.0	5.1	CVSS:4.0/AV:P/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 CN 4100

Classification

Weakness

CWE-284 Improper Access Control

References

cert-portal.siemens.com /productcert/html/ssa-416652.html
vendor-advisory

Sources

CVE List CVE-2025-40939
NVD CVE-2025-40939

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.

Summary