LibreNMS through 26.4.0 renders JSON fields (name, ip, model, author, commit message) returned by the admin-configurable Oxidized integration URL (oxidized.url) into the device showconfig page without applying htmlspecialchars(). An administrator who points the Oxidized URL at an attacker-controlled server (SSRF) can cause it to return malicious JSON, resulting in stored/persistent cross-site scripting affecting all users who view any device's showconfig tab. Fixed in 26.7.0.
{
"cna_assigner": "VulnCheck",
"cwe_ids": [
"CWE-79"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84189.json"
}{
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "26.7.0"
},
{
"fixed": "26.4.0"
}
],
"source": [
"AFFECTED_FIELD",
"DESCRIPTION"
]
}