A security flaw tracked as CVE-2026-48687 has been found in FastNetMon Community Edition, affecting all versions up to 1.2.9. The issue exists in the tool’s Juniper router integration plugin, and could allow unauthorized commands to run on servers where FastNetMon is installed. The problem occurs because the plugin builds log-related shell commands by inserting unvetted user input directly into the command lines with no checks or cleaning. This unvetted input comes from values passed to the plugin for attack IP address, traffic direction, and power level. In current default setups, the core FastNetMon tool only passes standard, safely formatted IP addresses, so the risk of exploitation is low right now. But if the plugin is run directly, triggered by another system, or if future FastNetMon updates pass input from untrusted sources, an attacker could craft malicious input to run arbitrary commands on the server. The recommended fix for this vulnerability is to either replace the command-running function with one that writes log entries directly without executing shell commands, or add proper input sanitization to all values used in the command lines.
Source: NVD (National Vulnerability Database) — https://nvd.nist.gov/vuln/detail/CVE-2026-48687