CVE-2026-48687

fastnetmon: FastNetMon Community Edition through 1.2.9 contains an OS command injection vulnerability in the Juniper router integ...

CVE-2026-48687 is fixed in fastnetmon on 1 platform, first by fastnetmon 1.2.8+git20250911-2ubuntu0.1~esm1, released May 26, 2026. It is not reported as exploited. Patch Radar priority: Urgent.

Urgent
CVSS
9.8
critical
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0165
76th percentile

FastNetMon Community Edition through 1.2.9 contains an OS command injection vulnerability in the Juniper router integration plugin. The _log() function in src/juniper_plugin/fastnetmon_juniper.php (lines 117-118) constructs shell commands by concatenating the $msg parameter directly into exec() calls: exec("echo `date` \"- {FASTNETMON] - " . $msg . " \" >> " . $FILE_LOG_TMP). The $msg variable contains unsanitized data derived from command-line arguments argv[1] through argv[3], which represent the attack IP address, direction, and power. While FastNetMon's C++ core currently passes IP addresses via inet_ntoa() (which only produces safe dotted-decimal notation), the PHP script performs no input validation or shell escaping. If the script is invoked directly, by another orchestration system, or if future code changes pass string-sourced IPs, arbitrary commands can be injected. The correct fix is to replace exec() with file_put_contents() or use escapeshellarg() on all parameters.

Where it's fixed

ProductFixed inFixReleased
Linux
fastnetmon · Debian 13.5 (trixie) 1.2.9-0+deb13u1 DEBIAN-CVE-2026-48687 Jun 24, 2026
fastnetmon · Debian 14 1.2.9-1 DEBIAN-CVE-2026-48687 Jun 24, 2026
fastnetmon · Ubuntu 20.04 LTS (focal) 1.1.4-1ubuntu0.1~esm1 fastnetmon 1.1.4-1ubuntu0.1~esm1 Jun 24, 2026
fastnetmon · Ubuntu 24.04.5 LTS (noble) 1.2.6-1ubuntu0.1~esm1 fastnetmon 1.2.6-1ubuntu0.1~esm1 Jun 24, 2026
fastnetmon · Ubuntu 26.04.1 LTS (resolute) 1.2.8+git20250911-2ubuntu0.1~esm1 fastnetmon 1.2.8+git20250911-2ubuntu0.1~esm1 May 26, 2026

Patch Radar data is free to use with attribution. Terms and how to credit it.

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.