How severe is CVE-2026-84188?

No CVSS score has been assigned to CVE-2026-84188 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-84188?

CVE-2026-84188 affects the following packages: librenms/librenms (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2026-84188?

Update librenms/librenms to 26.7.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-84188 is resolved across your whole dependency graph.

How do I detect CVE-2026-84188 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for librenms/librenms, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-84188 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2026-84188 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-84188 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-84188?

CVE-2026-84188 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 15th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-84188?

CVE-2026-84188 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-84188 published, and has it been updated?

CVE-2026-84188 was published on September 1, 2026 and was last updated on September 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

Not in CISA KEV

CVE-2026-84188 — librenms/librenms

CVE-2026-84188 is a Cross-site Scripting (XSS) vulnerability in librenms/librenms. A fix is available for librenms/librenms — see the affected versions and patch details below.

librenms before 26.7.0 Stored XSS via graph_descr settings

Also known asGHSA-7cj5-v4pp-v632

Published

Sep 1, 2026

Updated

Sep 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 2, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-84188.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs15th percentile — riskier than 15% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐘librenms/librenms

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

Summary

The graph_descr.<graphtype> family of settings is echoed verbatim without htmlspecialchars() in includes/html/pages/graphs.inc.php:194. Any admin can store a malicious HTML payload that executes in every authenticated user's browser viewing that graph type.

CVSS

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N — 4.8 Medium

Details

// graphs.inc.php:194
echo LibrenmsConfig::get('graph_descr.' . $vars['type']);

PoC

PUT /settings/graph_descr.device_processor
{"value": "<img src=x onerror=\"alert('ADV-15')\">"}

GET /graphs?type=device_processor
→ <img src=x onerror="alert('ADV-15')">

Fix

echo htmlspecialchars(LibrenmsConfig::get('graph_descr.' . $vars['type']), ENT_QUOTES, 'UTF-8');

Prerequisite

Admin session to set the config value.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`librenms/librenms`	all versions	26.7.0`composer require librenms/librenms:^26.7.0`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for librenms/librenms, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update librenms/librenms to 26.7.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-84188 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

### Summary The `graph_descr.<graphtype>` family of settings is echoed verbatim without `htmlspecialchars()` in `includes/html/pages/graphs.inc.php:194`. Any admin can store a malicious HTML payload that executes in every authenticated user's browser viewing that graph type. ### CVSS `CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N` — **4.8 Medium** ### Details ```php // graphs.inc.php:194 echo LibrenmsConfig::get('graph_descr.' . $vars['type']); ``` ### PoC ``` PUT /settings/graph_descr.device_processor {"value": "<img src=x onerror=\"alert('ADV-15')\">"} GET /graphs?type=device_processor →

O3 Security · Impact-Aware SCA

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