Vulnerability · Published May 26, 2026 · Assigned by mitre
CVE-2026-48695
High 8.1
In plain English
A high-severity OS command injection in the fastnetmon package (Debian). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.1% (higher than 65% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
FastNetMon Community Edition through 1.2.9 contains an OS command injection vulnerability in the MikroTik router integration plugin. The _log() function in src/mikrotik_plugin/fastnetmon_mikrotik.php (lines 107-108) constructs shell commands by concatenating the $msg parameter directly into exec() calls: exec("echo `date` \"- {FASTNETMON] - " . $msg . " \" >> " . $FILE_LOG_TMP). This is identical in pattern to the Juniper plugin vulnerability. The $msg variable contains unsanitized attack data from command-line arguments. An attacker who can influence argv[] values can inject arbitrary shell commands. The fix is to replace exec() with file_put_contents() or use escapeshellarg().
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | fastnetmon | no fix listed | DEBIAN-CVE-2026-48695 |
| Debian:13 | fastnetmon | 1.2.9-0+deb13u1 | DEBIAN-CVE-2026-48695 |
| Debian:14 | fastnetmon | 1.2.9-1 | DEBIAN-CVE-2026-48695 |
| Ubuntu:25.10 | fastnetmon | no fix listed | UBUNTU-CVE-2026-48695 |
| Ubuntu:26.10 | fastnetmon | no fix listed | UBUNTU-CVE-2026-48695 |
Affected products (as reported)
Weakness: CWE-78 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N