CriticalFix available

fastnetmon — security advisory

Type: advisorySources: OSVAdvisory ID: UBUNTU-CVE-2026-48687

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.

Products: fastnetmon
Affected versions: 1.1.4-1, 1.1.4-1build3, 1.1.4-1build4, 1.1.4-1build5, 1.2.5-1, 1.2.6-1, 1.2.6-1build1, 1.2.6-1build2, 1.2.6-1build3, 1.2.6-1build4, 1.2.8+git20250911-1, 1.2.8+git20250911-1build1, 1.2.8+git20250911-1build2, 1.2.8+git20250911-2, 1.2.8-1build1, 1.2.8-1build2, 1.2.9-1, 1.2.9-1build1, 1.2.9-1build2
Fixed versions: 1.1.4-1ubuntu0.1~esm1, 1.2.6-1ubuntu0.1~esm1, 1.2.8+git20250911-2ubuntu0.1~esm1
CVEs: CVE-2026-48687
Confirmed fixed CVEs: Not specified
Updated in this feed: 31 Oct 2026, 02:21 UTC · Revision 1

Source evidence

UBUNTU-CVE-2026-48687

core-osv · Original source

Published 26 May 2026, 16:16 UTC

osv:UBUNTU-CVE-2026-48687

fastnetmon

Fixed versions: 1.1.4-1ubuntu0.1~esm1

fastnetmon

Fixed versions: 1.2.6-1ubuntu0.1~esm1

fastnetmon

Fixed versions: Not specified

fastnetmon

Fixed versions: Not specified

fastnetmon

Fixed versions: 1.2.8+git20250911-2ubuntu0.1~esm1

Complete source record

{
  "id": "82d5a5d6af6b935114221cc0d72666de55074fd1f8d9ba77df765782344875a2",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-48687",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-48687",
    "summary": "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.",
    "evidence": "osv:UBUNTU-CVE-2026-48687",
    "products": [
      {
        "name": {
          "value": "fastnetmon",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "1.1.4-1ubuntu0.1~esm1",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "1.1.4-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.1.4-1build3",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.1.4-1build4",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.1.4-1build5",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "fastnetmon",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "1.2.6-1ubuntu0.1~esm1",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "1.2.5-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "1.2.6-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "1.2.6-1build1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "1.2.6-1build2",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "1.2.6-1build3",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "1.2.6-1build4",
            "evidence": "/affected/1/versions"
          }
        ]
      },
      {
        "name": {
          "value": "fastnetmon",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "1.2.8-1build1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "1.2.8-1build2",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "1.2.8+git20250911-1",
            "evidence": "/affected/2/versions"
          }
        ]
      },
      {
        "name": {
          "value": "fastnetmon",
          "evidence": "/affected/3/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "1.2.8+git20250911-2",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "1.2.9-1",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "1.2.9-1build1",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "1.2.9-1build2",
            "evidence": "/affected/3/versions"
          }
        ]
      },
      {
        "name": {
          "value": "fastnetmon",
          "evidence": "/affected/4/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "1.2.8+git20250911-2ubuntu0.1~esm1",
            "evidence": "/affected/4/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "1.2.8+git20250911-1",
            "evidence": "/affected/4/versions"
          },
          {
            "value": "1.2.8+git20250911-1build1",
            "evidence": "/affected/4/versions"
          },
          {
            "value": "1.2.8+git20250911-1build2",
            "evidence": "/affected/4/versions"
          },
          {
            "value": "1.2.8+git20250911-2",
            "evidence": "/affected/4/versions"
          }
        ]
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "UBUNTU-CVE-2026-48687",
      "aliases": [
        "UBUNTU-CVE-2026-48687"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        },
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"
        },
        {
          "type": "Ubuntu",
          "score": "medium"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1.1.4-1ubuntu0.1~esm1"
                }
              ]
            }
          ],
          "package": {
            "name": "fastnetmon",
            "purl": "pkg:deb/ubuntu/fastnetmon?arch=source&distro=esm-apps%2Ffocal",
            "ecosystem": "Ubuntu:Pro:20.04:LTS"
          },
          "versions": [
            "1.1.4-1",
            "1.1.4-1build3",
            "1.1.4-1build4",
            "1.1.4-1build5"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48687.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "fastnetmon",
                "binary_version": "1.1.4-1ubuntu0.1~esm1"
              }
            ],
            "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1.2.6-1ubuntu0.1~esm1"
                }
              ]
            }
          ],
          "package": {
            "name": "fastnetmon",
            "purl": "pkg:deb/ubuntu/fastnetmon?arch=source&distro=esm-apps%2Fnoble",
            "ecosystem": "Ubuntu:Pro:24.04:LTS"
          },
          "versions": [
            "1.2.5-1",
            "1.2.6-1",
            "1.2.6-1build1",
            "1.2.6-1build2",
            "1.2.6-1build3",
            "1.2.6-1build4"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48687.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "fastnetmon",
                "binary_version": "1.2.6-1ubuntu0.1~esm1"
              }
            ],
            "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "fastnetmon",
            "purl": "pkg:deb/ubuntu/fastnetmon?arch=source&distro=questing",
            "ecosystem": "Ubuntu:25.10"
          },
          "versions": [
            "1.2.8-1build1",
            "1.2.8-1build2",
            "1.2.8+git20250911-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48687.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "fastnetmon",
                "binary_version": "1.2.8+git20250911-1"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "fastnetmon",
            "purl": "pkg:deb/ubuntu/fastnetmon?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "1.2.8+git20250911-2",
            "1.2.9-1",
            "1.2.9-1build1",
            "1.2.9-1build2"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48687.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "fastnetmon",
                "binary_version": "1.2.9-1build2"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1.2.8+git20250911-2ubuntu0.1~esm1"
                }
              ]
            }
          ],
          "package": {
            "name": "fastnetmon",
            "purl": "pkg:deb/ubuntu/fastnetmon?arch=source&distro=esm-apps%2Fresolute",
            "ecosystem": "Ubuntu:Pro:26.04:LTS"
          },
          "versions": [
            "1.2.8+git20250911-1",
            "1.2.8+git20250911-1build1",
            "1.2.8+git20250911-1build2",
            "1.2.8+git20250911-2"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48687.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "fastnetmon",
                "binary_version": "1.2.8+git20250911-2ubuntu0.1~esm1"
              }
            ],
            "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
          }
        }
      ],
      "modified": "2026-10-17T12:58:31.113996270Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-48687"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-48687",
        "https://www.cve.org/CVERecord?id=CVE-2026-48687",
        "https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48687-juniper-cmd-injection",
        "https://github.com/pavel-odintsov/fastnetmon/pull/1049",
        "https://github.com/pavel-odintsov/fastnetmon/commit/6f58184fb60248df011c4c379bf445e07609ad27",
        "https://github.com/pavel-odintsov/fastnetmon",
        "https://github.com/pavel-odintsov/fastnetmon/blob/master/src/juniper_plugin/fastnetmon_juniper.php",
        "https://ubuntu.com/security/notices/USN-8429-1"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-48687",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 358684,
  "published_at": "2026-05-26T16:16:00+00:00"
}