CVE-2025-40941: Siemens SIMATIC CN 4100 · Information Exposure
Affects Siemens SIMATIC CN 4100Source CVE Database V5
Not known to be exploited · CVSS 4.3 Medium.
Data as of 26 Oct 2026, 06:26 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 20% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:NExploitation evidence
Disclosed: evidence found.
CVE published 9 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Siemens SIMATIC CN 4100 | Affected
| Fixed in– |
AI-suggested
To mitigate CVE-2025-40941, European organizations should implement a combination of technical and procedural controls. First, upgrade SIMATIC CN 4100 devices to version 4.0.1 or later once Siemens releases the patch to eliminate the vulnerability. Until a patch is available, restrict network access to the affected devices by implementing strict network segmentation and firewall rules that limit management interface exposure only to trusted administrators. Employ virtual LANs (VLANs) and access control lists (ACLs) to isolate industrial control systems from general IT networks and the internet. Monitor network traffic for unusual or unauthorized queries to the SIMATIC CN 4100 devices that could indicate reconnaissance attempts. Conduct regular vulnerability assessments and penetration testing focused on ICS environments to identify and remediate information disclosure risks. Additionally, maintain an up-to-date asset inventory and ensure that all devices are configured following Siemens' security best practices. Training and awareness for operational technology personnel on recognizing and responding to suspicious network activity can further reduce risk.
Description
A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1). The affected devices exposes server information in its responses. This could allow an attacker with network access to gain useful information, increasing the likelihood of targeted attacks.