XSS in Librenms
CVE-2026-84189
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (30.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 30.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/librenms/librenms/security/advisories/GHSA-7gww-x7fh-jf9j (vendor-advisory)
- www.vulncheck.com/advisories/librenms-before-26.7.0-stored-xss-via-oxidized-api (third-party-advisory)
Frequently asked questions
- What is CVE-2026-84189?
- CVE-2026-84189 is a high-severity vulnerability in Librenms, classified under Cross-site Scripting. CVSS score: 8.1/10. Published 2026-09-01.
- How severe is CVE-2026-84189?
- High severity. CVSS v3 base score is 8.1 out of 10.