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PatchSiren cyber security CVE debrief

CVE-2025-40949 Siemens CVE debrief

CVE-2025-40949 affects Siemens RUGGEDCOM ROX devices exposed through the Web UI Scheduler function. According to the CISA-published advisory, user-supplied input is not properly sanitized, which can let commands be injected into the task scheduling backend. The impact is severe: an authenticated remote attacker could execute arbitrary commands with root privileges on the underlying operating system. Siemens’ remediation is to update to V2.17.1 or later.

Vendor
Siemens
Product
RUGGEDCOM ROX MX5000
CVSS
CRITICAL 9.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-12
Original CVE updated
2026-05-14
Advisory published
2026-05-12
Advisory updated
2026-05-14

Who should care

OT/ICS operators, plant engineers, and security teams managing Siemens RUGGEDCOM ROX MX5000 and related ROX devices listed in the advisory, especially environments where the Web UI is reachable by authenticated users.

Technical summary

The advisory describes a command-injection issue in the Scheduler functionality of the device Web UI. Because the backend does not properly sanitize user-controlled input, an attacker who can authenticate and reach the Web UI may be able to inject operating-system commands through scheduling requests. The published CVSS 3.1 vector is AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H, yielding a 9.1 Critical score. The described impact includes arbitrary command execution with root privileges.

Defensive priority

Urgent — apply the vendor fix as soon as practical and reduce access to the Web UI until patched.

Recommended defensive actions

  • Update affected devices to V2.17.1 or later, per Siemens remediation guidance.
  • Restrict Web UI access to trusted administrative networks and least-privilege accounts.
  • Review scheduler-related configuration and audit device logs for unexpected job or command activity.
  • Verify exposure across all ROX models listed in the advisory and prioritize remediation for internet-facing or widely reachable management interfaces.
  • Follow CISA ICS recommended practices for segmentation, access control, and defense-in-depth while remediation is underway.

Evidence notes

This debrief is based on the CISA CSAF advisory ICSA-26-134-12 (republished from Siemens ProductCERT SSA-081142) and the supplied advisory metadata. The source description states that the Web UI Scheduler input is not properly sanitized and that successful exploitation can lead to arbitrary command execution with root privileges. The advisory was published on 2026-05-12 and modified on 2026-05-14. No KEV listing was supplied for this CVE.

Sources and references

Verified primary and authoritative sources

  • CVE-2025-40949 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2025-40949

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2025-40949 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2025-40949

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2026/icsa-26-134-12.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/csaf/ssa-081142.json

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/html/ssa-081142.html

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-26-134-12

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-alerts/ics-alert-10-301-01

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/resources-tools/resources/ics-recommended-practices

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/topics/industrial-control-systems

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf

    Reference

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.