Cross-site scripting in LibreNMS - #VU140842
Published: August 4, 2026
Vulnerability identifier: #VU140842
CSH Severity: Medium
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: N/A
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary script in a victim's browser.
The vulnerability exists due to cross-site scripting in the VLAN name display page when rendering SNMP-sourced VLAN names in HTML. A remote attacker can supply a specially crafted VLAN name to execute arbitrary script in a victim's browser.
The advisory identifies this as an additional vulnerable entry point following the same SNMP-sourced data flow pattern.
Affected software
LibreNMS
Remediation
Install security update from vendor's website.
LibreNMS - update to 26.5.0