CVE-2026-26991
MEDIUM
GHSA-5pqf-54qp-32wx
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Lifecycle Timeline
4Description
LibreNMS is an auto-discovering PHP/MySQL/SNMP based network monitoring tool. In versions 26.1.1 and below, the device group name is not sanitized, allowing attackers with admin privileges to perform Stored Cross-Site Scripting (XSS) attacks. When a user adds a device group, an HTTP POST request is sent to the Request-URI "/device-groups". The name of the newly created device group is stored in the value of the name parameter. After the device group is created, the entry is displayed along with relevant buttons such as Rediscover Devices, Edit, and Delete. This issue has been fixed in version 26.2.0.
Analysis
Stored XSS in LibreNMS versions 26.1.1 and below allows authenticated administrators to inject malicious scripts through unsanitized device group names, which execute when other users view the group management interface. Public exploit code exists for this vulnerability, affecting LibreNMS deployments across multiple supported platforms. …
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Remediation
Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Verify Content-Security-Policy and output encoding.
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External POC / Exploit Code
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