CVE-2026-109356 librenms CVE debrief

Who should care

LibreNMS administrators and users with global-read accounts should assess exposure and verify inventory to mitigate the risk of unauthorized port deletion via PortsController::purge. Security teams and vulnerability management teams should review the vulnerability and implement compensating controls for exposed systems.

Why it matters

LibreNMS before 26.9.0 contains a missing authorization vulnerability in PortsController::purge that allows global-read users to physically delete ports without delete privileges.

• Verify inventory for LibreNMS installations, especially those with global-read user accounts.
• Assess exposure to unauthorized port deletion via PortsController::purge.

Technical summary

LibreNMS before 26.9.0 contains a missing authorization vulnerability in PortsController::purge that allows global-read users to physically delete ports without delete privileges. This vulnerability affects LibreNMS installations with global-read user accounts, potentially allowing unauthorized port deletion via PortsController::purge. The vulnerability is grounded in the lack of proper authorization checks in the PortsController::purge functionality, which can lead to unintended port deletions and potential disruptions in network management.

Defensive priority

Assess exposure and verify inventory for LibreNMS installations, especially those with global-read user accounts.

Recommended defensive actions

• Assess exposure and verify inventory for LibreNMS installations, especially those with global-read user accounts.
• Verify that LibreNMS installations are updated to version 26.9.0 or later.
• Restrict access to the PortsController::purge functionality to authorized users only.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The CVE record and source item provide details on the missing authorization vulnerability in LibreNMS before 26.9.0. Evidence is limited to CVE Program and source item descriptions. Defenders should verify affected scope, severity, and vendor guidance through official advisories. The vulnerability allows global-read users to delete ports without delete privileges, potentially impacting inventory management and device configuration.

Sources and 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.