CVE-2026-84189
HIGHCVE-2026-84189 is a high-severity (CVSS 8.1) Cross-site Scripting (XSS) vulnerability. O3 Security confirms whether CVE-2026-84189 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
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…
Description
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.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-84189 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-84189 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-84189. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-84189 in your dependencies?
O3 detects CVE-2026-84189 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.