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Medium

LibreNMS allows stored XSS in Alert Template name field

  • Disclosed: 18.08.2025
  • Updated: 11.10.2026 10:22

Summary

A stored Cross-Site Scripting (XSS) vulnerability exists in LibreNMS (<= 25.6.0) in the Alert Template creation feature. This allows a user with the admin role to inject malicious JavaScript, which will be executed when the template is rendered, potentially compromising other admin accounts.

Details

In the LibreNMS web UI, when a user with the admin role visits /templates and clicks "Create new alert template", the "Template name" field fails to properly sanitize input. By inserting a payload like:

&lt;script>alert(document.cookie)&lt;/script>

and filling the other fields with arbitrary content (e.g., test), once the template is saved, the script is executed. This confirms that user input is stored and later rendered without proper output encoding.

This vulnerability can be exploited for session hijacking, data theft, or other malicious actions targeting other admin users.

PoC

  1. Log in to LibreNMS using an account with the admin role.

  2. Navigate to: http://localhost:8000/templates.

  3. Click the "Create new alert template" button.

  4. Input the following into the Template name field:

    &lt;script>alert(document.cookie)&lt;/script>

  5. Fill the remaining fields (Template, Alert title, Recovery title) with arbitrary content such as test.

  6. Click "Create template".

  7. Upon saving, a JavaScript alert pops up, confirming the stored XSS is triggered. <img width="1574" height="848" alt="image" src="https://github.com/user-attachments/assets/bc482874-c47e-48e3-83b6-cb4a9dcf4a53" />

Impact

Type: Stored Cross-Site Scripting (XSS) Affected users: Only accounts with the admin role who access the Alert Templates page (http://localhost:8000/templates) are affected. Attackers need: Authenticated admin-level access.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Composer package librenms/librenms < 25.8.0 25.8.0

References

CVSS score 5.5/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N
Weakness (CWE)
CWE-79
Platform
Composer
Package
librenms/librenms
Disclosed
18.08.2025
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-vxq6-8cwm-wj99 - 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

Severity:
  1. LibreNMS — Stored XSS via SNMP/Syslog Data in Legacy Templates
    High · 7.1 CVE-2026-84192 < 26.5.0 26.5.0
  2. LibreNMS: SSRF-driven stored XSS via Oxidized API response fields in device showconfig page
    High · 8.1 CVE-2026-84189 < 26.7.0 26.7.0
  3. LibreNMS Vulnerable to Remote Code Execution by Signal Alert Transportation module
    High CVE-2026-55182 >= 21.6.0, < 26.5.0 26.5.0
  4. LibreNMS is Vulnerable to Remote Code Execution by Arbitrary File Write
    High CVE-2026-6204 >= 1.48, < 26.3.0 26.3.0
  5. LibreNMS has a Time-Based Blind SQL Injection in address-search.inc.php
    High · 8.8 CVE-2026-26990 < 26.2.0 26.2.0
  6. LibreNMS: SQL Injection in ajax_table.php spreads through a covert data stream.
    High CVE-2026-26988 < 26.2.0 26.2.0
  7. LibreNMS contains an authenticated SQL Injection vulnerability
    High · 7.1 CVE-2020-36947 <= 1.46 no fix
  8. LibreNMS allows stored XSS in Alert Template name field this entry
    Medium · 5.5 CVE-2025-55296 < 25.8.0 25.8.0
  9. LibreNMS has Authenticated Remote File Inclusion in ajax_form.php that Allows RCE
    High · 7.5 CVE-2025-54138 < 25.7.0 25.7.0
  10. LibreNMS has a Stored XSS ('Cross-site Scripting') in librenms/includes/html/pages/device/services.inc.php
    High · 7.5 CVE-2024-52526 < 24.10.0 24.10.0
  11. LibreNMS has an Authenticated OS Command Injection
    Critical · 9.1 CVE-2024-51092 < 24.10.0 24.10.0
  12. LibreNMS has a Stored XSS ('Cross-site Scripting') in librenms/includes/html/print-customoid.php
    High · 7.5 CVE-2024-51497 < 24.10.0 24.10.0
  13. LibreNMS has a Reflected XSS ('Cross-site Scripting') in librenms/includes/html/pages/wireless.inc.php
    High · 7.5 CVE-2024-51496 < 24.10.0 24.10.0
  14. LibreNMS has a Stored XSS ('Cross-site Scripting') in librenms/includes/html/dev-overview-data.inc.php
    High · 7.5 CVE-2024-51495 < 24.10.0 24.10.0
  15. LibreNMS has a Stored XSS ('Cross-site Scripting') in librenms/app/Http/Controllers/Table/EditPortsController.php
    High · 7.5 CVE-2024-51494 < 24.10.0 24.10.0
  16. LibreNMS has a Persistent XSS from Insecure Input Sanitization Affects Multiple Endpoints
    High · 7.2 CVE-2024-50355 < 24.10.0 24.10.0
  17. LibreNMS has a Stored XSS ('Cross-site Scripting') in librenms/includes/html/pages/device/overview/services.inc.php
    High · 7.5 CVE-2024-50352 < 24.10.0 24.10.0
  18. LibreNMS has a Reflected XSS ('Cross-site Scripting') in librenms/includes/functions.php
    High · 7.5 CVE-2024-50351 < 24.10.0 24.10.0
  19. LibreNMS has a Stored XSS ('Cross-site Scripting') in librenms/app/Http/Controllers/Table/EditPortsController.php
    High · 7.5 CVE-2024-50350 < 24.10.0 24.10.0
  20. LibreNMS has a Stored XSS ('Cross-site Scripting') in librenms/includes/html/pages/device/capture.inc.php
    High · 7.5 CVE-2024-49764 < 24.10.0 24.10.0
  21. Stored XSS ('Cross-site Scripting') in librenms/includes/html/pages/edituser.inc.php
    High · 7.5 CVE-2024-49759 < 24.10.0 24.10.0
  22. LibreNMS has a stored XSS ('Cross-site Scripting') in librenms/includes/html/pages/api-access.inc.php
    High · 7.5 CVE-2024-49754 < 24.10.0 24.10.0
  23. LibreNMS has Stored Cross-site Scripting vulnerability in "Device Group" Name
    High · 7.2 CVE-2024-47524 < 24.9.0 24.9.0
  24. LibreNMS vulnerable to a Time-Based Blind SQL injection leads to database extraction
    High · 7.2 CVE-2024-32480 < 24.4.0 24.4.0
  25. LibreNMS uses Improper Sanitization on Service template name leads to Stored XSS
    High · 7.1 CVE-2024-32479 < 24.4.0 24.4.0
  26. LibreNMS vulnerable to SQL injection time-based leads to database extraction
    High · 8.8 CVE-2024-32461 < 24.4.0 24.4.0
  27. SQL injection in librenms/librenms
    High · 7.8 CVE-2023-5591 < 23.10.0 23.10.0
  28. Cross site scripting in librenms
    High · 8.4 CVE-2023-5060 < 23.9.1 23.9.1
  29. LibreNMS Cross-site Scripting vulnerability
    High · 7.6 CVE-2023-4347 < 23.8.0 23.8.0
  30. Deserialization of Untrusted Data in librenms/librenms
    High · 8.8 CVE-2022-3525 < 22.10.0 22.10.0
  31. Cross-site Scripting in librenms/librenms
    High · 7.6 CVE-2022-4068 < 22.10.0 22.10.0
  32. Insufficient Session Expiration in librenms/librenms
    Critical · 9.8 CVE-2022-4070 < 22.10.0 22.10.0
  33. Command injection in librenms
    High CVE-2022-29712 < 22.4.0 22.4.0
  34. LibreNMS Information Disclosure
    Critical · 9.8 CVE-2019-10665 <= 1.47 no fix
  35. LibreNMS arbitrary OS commands execution
    Critical · 9.8 CVE-2018-20434 = 1.46 no fix
  36. LibreNMS SQL Injection
    High · 8.8 CVE-2018-20678 < 1.65 1.65
  37. Improper Access Control in librenms
    High · 7.1 CVE-2022-0580 < 22.2.0 22.2.0
  38. Improper Authorization in librenms
    High · 7.1 CVE-2022-0587 < 22.2.0 22.2.0
  39. Path traversal in librenms/librenms
    Critical · 9.8 CVE-2021-44278 <= 21.11.0 no fix
  40. Exposure of Resource to Wrong Sphere in LibreNMS
    High · 8.8 CVE-2020-15877 < 1.65.1 1.65.1
  41. SQL Injection in librenms
    High · 8.8 CVE-2020-35700 < 21.1.0 21.1.0
  42. SQL Injection in LibreNMS
    High · 8.8 CVE-2019-10671 < 1.50.1 1.50.1
  43. SQL Injection in LibreNMS
    High · 8.1 CVE-2019-12465 < 1.53 1.53
  44. Path Traversal in LibreNMS
    High · 7.5 CVE-2019-12464 < 1.53 1.53
  45. Improper Encoding or Escaping of Output and Injection in LibreNMS
    High · 8.8 CVE-2019-12463 >= 1.50.1, < 1.53 1.53

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