In LibreNMS < 21.3.0, a stored XSS vulnerability was identified in the API Access page due to insufficient sanitization of the $api->description variable. As a result, arbitrary Javascript code can get executed.
A second-order SQL injection issue in Widgets/TopDevicesController.php (aka the Top Devices dashboard widget) of LibreNMS before 21.1.0 allows remote authenticated attackers to execute arbitrary SQL commands via the sort_order parameter against the /ajax/form/widget-settings endpoint.
An issue was discovered in LibreNMS before 1.65.1. It has insufficient access control for normal users because of "'guard' => 'admin'" instead of "'middleware' => ['can:admin']" in routes/web.php.
An issue was discovered in LibreNMS through 1.47. Many of the scripts rely on the function mysqli_escape_real_string for filtering data. However, this is particularly ineffective when returning user supplied input in an HTML or a JavaScript context, resulting in unsafe data being injected into these contexts, leading to attacker controlled JavaScript executing in the browser. One example of this is the string parameter in html/pages/inventory.inc.php.