OpenNMS version 18.0.1 and prior are vulnerable to a stored XSS issue due to insufficient filtering of SNMP agent supplied data. By creating a malicious SNMP 'sysName' or 'sysContact' response, an attacker can store an XSS payload which will trigger when a user of the web UI views the data. This issue was fixed in version 18.0.2, released on September 20, 2016.
Severity
CVSS 3.1
6.1 medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS
0.8% chance of exploitation in the next 30 days; higher than 57% of CVEs (scores of 2026-10-31)