{
  "cveId": "CVE-2026-48691",
  "url": "https://patchblox.com/security/cve/CVE-2026-48691",
  "summary": "CVE-2026-48691 is fixed in fastnetmon on 1 platform, first by fastnetmon 1.2.8\u002Bgit20250911-2ubuntu0.1~esm1, released May 26, 2026. It is not reported as exploited. Patch Radar priority: Urgent.",
  "title": "fastnetmon: FastNetMon Community Edition through 1.2.9 contains an integer overflow in the BGP AS_PATH attribute encoder",
  "description": "FastNetMon Community Edition through 1.2.9 contains an integer overflow in the BGP AS_PATH attribute encoder. In src/bgp_protocol.hpp, the IPv4UnicastAnnounce::get_attributes() function computes attribute_length as \u0027sizeof(bgp_as_path_segment_element_t) \u002B this-\u003Eas_path_asns.size() * sizeof(uint32_t)\u0027 and stores it in a uint8_t field (line 600-605). Since uint8_t can only hold values 0-255, an AS_PATH containing more than 63 ASNs (2 \u002B 64*4 = 258 \u003E 255) causes silent truncation. The truncated length is used for buffer sizing, while the actual data written is the full untruncated amount, resulting in a heap buffer overflow. Similarly, the path_segment_length field at line 621 is also uint8_t, truncating with more than 255 ASNs.",
  "published": "2026-05-26T10:16:00Z",
  "severity": "critical",
  "cvss": 9.8,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.00308,
  "epssPercentile": 0.23816,
  "priority": "Urgent",
  "priorityTier": 2,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "fastnetmon",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "1.2.9-0\u002Bdeb13u1",
      "fix": "DEBIAN-CVE-2026-48691",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-48691",
      "released": "2026-06-24T14:07:24Z"
    },
    {
      "platform": "linux",
      "product": "fastnetmon",
      "release": "Debian 14",
      "fixedVersion": "1.2.9-1",
      "fix": "DEBIAN-CVE-2026-48691",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-48691",
      "released": "2026-06-24T14:07:24Z"
    },
    {
      "platform": "linux",
      "product": "fastnetmon",
      "release": "Ubuntu 24.04.5 LTS (noble)",
      "fixedVersion": "1.2.6-1ubuntu0.1~esm1",
      "fix": "fastnetmon 1.2.6-1ubuntu0.1~esm1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-noble-fastnetmon-1.2.6-1ubuntu0.1-esm1",
      "released": "2026-06-24T14:07:41Z"
    },
    {
      "platform": "linux",
      "product": "fastnetmon",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "1.2.8\u002Bgit20250911-2ubuntu0.1~esm1",
      "fix": "fastnetmon 1.2.8\u002Bgit20250911-2ubuntu0.1~esm1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-fastnetmon-1.2.8-git20250911-2ubuntu0.1-esm1",
      "released": "2026-05-26T12:16:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T01:18:40Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}