CVE-2025-40940 Information disclosure in SIMATIC CN 4100

What is CVE-2025-40940?

CVE-2025-40940 is a medium-severity vulnerability in Siemens SIMATIC CN 4100, published on 9 Dec 2025. An attacker needs administrator access to exploit it, with no action from the victim.

Official description

A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1). The affected application exhibits inconsistent SNMP behavior, such as unexpected service availability and unreliable configuration handling across protocol versions. This could allow an attacker to access sensitive data, potentially leading to a breach of confidentiality.

Weakness: CWE-200

Which versions are affected by CVE-2025-40940?

It affects 1 product.

Products include Siemens Simatic Cn 4100 Firmware.

How do I fix CVE-2025-40940?

No fix has been published for CVE-2025-40940 yet. Limit exposure of the affected software until one is available.

Is CVE-2025-40940 being exploited?

There is no known exploitation of CVE-2025-40940 in the wild and no public exploit code.

Other vulnerabilities in Siemens SIMATIC CN 4100

• CVE-2024-32741 Hardcoded credentials in SIMATIC CN 4100 Critical 10.0
• CVE-2023-29130 Privilege escalation in SIMATIC CN 4100 Critical 9.9
• CVE-2024-32740 Hardcoded credentials in SIMATIC CN 4100 Critical 9.8
• CVE-2023-49621 Hardcoded credentials in SIMATIC CN 4100 Critical 9.8
• CVE-2025-40938 Hardcoded credentials in SIMATIC CN 4100 Critical 9.2

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-2cx9-pwfc-xwx3.