CVE-2025-62411

LibreNMS <= 25.8.0 contains a Stored Cross-Site Scripting (XSS) vulnerability in the Alert Transports management functionality. When an administrator creates a new Alert Transport, the value of the Transport name field is stored and later rendered in the Transports column of the Alert Rules page without proper input validation or output encoding. This leads to arbitrary JavaScript execution in the admin’s browser.

Details

• Injection point: Transport name field in /alert-transports.
• Execution point: Transports column in /alert-rules.
• Scope: Only administrators can create Alert Transports, and only administrators can view the affected Alert Rules page. Therefore, both exploitation and impact are limited to admin users.

Steps to reproduce

1. Log in with an administrator account.

2. Navigate to:

   http://localhost:8000/alert-transports
   

3. Click Create alert transport and provide the following values:

   • Transport name:

     'onfocus='alert(1)' autofocus=
     

   • Default Alert: ON

   • Email: [email protected] (or any valid email)

   Save the transport.

4. Navigate to http://localhost:8000/alert-rules. A popup alert(1) is triggered, confirming that the payload executes.

Only accounts with the admin role who access the Alert Rules page (http://localhost:8000/alert-rules) are affected.

Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.

CVE-2025-62411 has a CVSS score of 5.5 (Medium). The vector is network-reachable, high 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 (25.10.0); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2025-62411? CVE-2025-62411 is a medium-severity cross-site scripting (XSS) vulnerability in librenms/librenms (composer), affecting versions < 25.10.0. It is fixed in 25.10.0. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
2. How severe is CVE-2025-62411? CVE-2025-62411 has a CVSS score of 5.5 (Medium). 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-2025-62411? librenms/librenms (composer) versions < 25.10.0 is affected.
4. Is there a fix for CVE-2025-62411? Yes. CVE-2025-62411 is fixed in 25.10.0. Upgrade to this version or later.
5. Is CVE-2025-62411 exploitable, and should I be worried? Whether CVE-2025-62411 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-2025-62411 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-2025-62411? Upgrade librenms/librenms to 25.10.0 or later.