How severe is CVE-2025-40771?

CVE-2025-40771 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-40771 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2025-40771?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2025-40771 have an EU (EUVD) identifier?

Yes. CVE-2025-40771 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-34160.

When was CVE-2025-40771 published?

CVE-2025-40771 was published on 2025-10-14 and last updated on 2026-06-17.

CVE-2025-40771

CVE-2025-40771 is a critical-severity vulnerability with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-306.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 9.3
EPSS exploit prediction: 0% (38th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-34160
Weakness: CWE-306
Published: 2025-10-14
Last modified: 2026-06-17

Description

A vulnerability has been identified in SIMATIC CP 1542SP-1 (6GK7542-6UX00-0XE0) (All versions < V2.4.24), SIMATIC CP 1542SP-1 IRC (6GK7542-6VX00-0XE0) (All versions < V2.4.24), SIMATIC CP 1543SP-1 (6GK7543-6WX00-0XE0) (All versions < V2.4.24), SIPLUS ET 200SP CP 1542SP-1 IRC TX RAIL (6AG2542-6VX00-4XE0) (All versions < V2.4.24), SIPLUS ET 200SP CP 1543SP-1 ISEC (6AG1543-6WX00-7XE0) (All versions < V2.4.24), SIPLUS ET 200SP CP 1543SP-1 ISEC TX RAIL (6AG2543-6WX00-4XE0) (All versions < V2.4.24). Affected devices do not properly authenticate configuration connections. This could allow an unauthenticated remote attacker to access the configuration data.

Frequently asked questions

What is CVE-2025-40771?: A vulnerability has been identified in SIMATIC CP 1542SP-1 (6GK7542-6UX00-0XE0) (All versions < V2.4.24), SIMATIC CP 1542SP-1 IRC (6GK7542-6VX00-0XE0) (All versions < V2.4.24), SIMATIC CP 1543SP-1 (6GK7543-6WX00-0XE0) (All versions < V2.4.24), SIPLUS ET 200SP CP 1542SP-1 IRC TX RAIL (6AG2542-6VX00-4XE0) (All versions < V2.4.24), SIPLUS ET 200SP CP 1543SP-1 ISEC (6AG1543-6WX00-7XE0) (All versions < V2.4.24), SIPLUS ET 200SP CP 1543SP-1 ISEC TX RAIL (6AG2543-6WX00-4XE0) (All versions < V2.4.24). Affected devices do not properly authenticate configuration connections. This could allow an unauthenticated remote attacker to access the configuration data.
How severe is CVE-2025-40771?: CVE-2025-40771 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-40771 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-40771?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2025-40771 have an EU (EUVD) identifier?: Yes. CVE-2025-40771 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-34160.
When was CVE-2025-40771 published?: CVE-2025-40771 was published on 2025-10-14 and last updated on 2026-06-17.

References

https://cert-portal.siemens.com/productcert/html/ssa-486936.html

Other CWE-306 (Missing Authentication for Critical Function) vulnerabilities

CVE-2026-54309 — Critical (CVSS 10.0): n8n is an open source workflow automation platform. Prior to 2.25.7 and 2.26.2, when @n8n/mcp-browser is run in HTTP…
CVE-2026-50242 — Critical (CVSS 10.0): In JetBrains Hub before 2026.1.13757, 2025.3.148033, 2025.2.148048, 2025.1.148120, 2024.3.148430, 2024.2.148429…
CVE-2026-49257 — Critical (CVSS 10.0): mcp-pinot is a Python-based Model Context Protocol (MCP) server for interacting with Apache Pinot. In versions 3.0.1…
CVE-2026-46846 — Critical (CVSS 10.0): Vulnerability in the Oracle WebCenter Portal product of Oracle Fusion Middleware (component: Security Framework).…
CVE-2026-46803 — Critical (CVSS 10.0): Vulnerability in the Oracle WebCenter Portal product of Oracle Fusion Middleware (component: Security Framework).…
CVE-2026-46800 — Critical (CVSS 10.0): Vulnerability in the Oracle WebCenter Sites product of Oracle Fusion Middleware (component: WebCenter Sites).…

Browse all CWE-306 (Missing Authentication for Critical Function) vulnerabilities →