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PatchSiren cyber security CVE debrief

CVE-2026-41551 Siemens CVE debrief

CVE-2026-41551 is a critical path traversal issue in Siemens ROS# versions before 2.2.2. CISA’s advisory says unsanitized user input can let a remote attacker access arbitrary files on the device. The advisory was first published on 2026-05-12 and republished on 2026-05-14 to incorporate Siemens ProductCERT’s SSA-357982 notice.

Vendor
Siemens
Product
ROS#
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 using Siemens ROS#, asset owners exposing file_server, and defenders responsible for network segmentation and patch management should prioritize this issue. It is especially relevant where ROS# is reachable from less-trusted networks or used beyond its intended file-transfer role.

Technical summary

The advisory describes a path traversal flaw caused by improper sanitization of user input. In affected Siemens ROS# versions before 2.2.2, a remote attacker could exploit this weakness to access arbitrary files on the device. The published CVSS vector is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N, indicating network reachability with no privileges or user interaction required and high confidentiality and integrity impact.

Defensive priority

Immediate

Recommended defensive actions

  • Update Siemens ROS# to v2.2.2 or later.
  • If patching is delayed, run file_server on a trusted network only.
  • Run file_server with appropriate user rights.
  • Use file_server only for its intended URDF-transfer task, not as a continuously running background service.
  • Use file_server only when manual file transfer is not possible.

Evidence notes

Based on CISA’s republished CSAF advisory ICSA-26-134-08 and Siemens ProductCERT advisory SSA-357982, both describing the same path traversal issue in Siemens ROS# before 2.2.2. The advisory references CWE-23 and a CVSS 3.1 vector of AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. The vendor field in the intake data is low-confidence and needs review; the advisory text itself supports Siemens ROS# as the affected product.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-41551 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-41551

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

  • CVE-2026-41551 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-41551

    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-26-134-08.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/csaf/ssa-357982.json

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/html/ssa-357982.html

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-26-134-08

    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.