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PatchSiren cyber security CVE debrief

CVE-2026-40456 LMS CVE debrief

CVE-2026-40456 is a HIGH-severity OS Command Injection vulnerability in LMS (LAN Management System) before commit 9fcb4de. The vulnerability allows attackers to execute arbitrary operating system commands due to improper validation of an IP address parameter passed to the 'exec()' function. This issue was published on June 18, 2026, and has a CVSS score of 8.6. Organizations using LMS should review their systems and apply necessary patches or updates. The vulnerability was reported by an unknown vendor and has been documented in various sources, including the CVE record and NVD detail pages.

Vendor
LMS
Product
Unknown
CVSS
HIGH 8.6
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-18
Original CVE updated
2026-06-22
Advisory published
2026-06-18
Advisory updated
2026-06-22

Who should care

Administrators and security teams responsible for managing LMS (LAN Management System) installations should be aware of this vulnerability. This includes organizations that use LMS for network management and may be exposed to potential attacks. Additionally, security researchers and penetration testers may be interested in this vulnerability for testing and validation purposes.

Technical summary

The OS Command Injection vulnerability in LMS (LAN Management System) occurs when an IP address parameter is passed to the 'exec()' function without proper validation. This allows attackers to inject and execute arbitrary operating system commands. The vulnerability has been assigned a CVSS score of 8.6, indicating a HIGH severity level. The affected version of LMS is before commit 9fcb4de. The vulnerability can be exploited by attackers with low privileges and does not require user interaction.

Defensive priority

HIGH

Recommended defensive actions

  • Review LMS installations and ensure they are updated to a version after commit 9fcb4de.
  • Implement proper input validation and sanitization for IP address parameters.
  • Use secure coding practices to prevent OS command injection vulnerabilities.
  • Monitor LMS systems for suspicious activity and potential attacks.
  • Apply patches or updates as soon as they are available.
  • Conduct regular security audits and vulnerability assessments.

Evidence notes

The information provided is based on the CVE record and NVD detail pages. The vulnerability was reported by an unknown vendor and has a low confidence level. The evidence is limited to the information available in the CVE and NVD records.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-40456 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-40456

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

  • CVE-2026-40456 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-40456

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

Supplemental references

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.