{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:pavel-odintsov:fastnetmon:*:*:*:*:community:*:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "1.2.9"
              },
              {
                "last_affected": "1.2.9"
              }
            ],
            "source": [
              "DESCRIPTION",
              "CPE_RANGE"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "394fbe06d112f9609d3d1cb10d60cbf98347c96a"
            }
          ],
          "repo": "https://github.com/pavel-odintsov/fastnetmon",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "mitre",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48685.json"
  },
  "details": "FastNetMon Community Edition through 1.2.9 has out-of-bounds memory access because it incorrectly parses BGP path attributes with the extended length flag set. In src/bgp_protocol.hpp, the parse_raw_bgp_attribute() function correctly identifies when extended_length_bit is set and sets length_of_length_field to 2, but then reads only a single byte for the attribute value length (attribute_value_length = value[2] at line 173). Per RFC 4271 Section 4.3, when the Extended Length bit is set, the Attribute Length field is two octets and the value should be read as a 16-bit big-endian integer from value[2] and value[3]. As a result, any attribute longer than 255 bytes has its length silently truncated to the low byte (e.g., 300 bytes = 0x012C is read as 0x2C = 44 bytes). The remaining 256 bytes are then misinterpreted as subsequent attributes, causing cascading parse failures and potential out-of-bounds memory access.",
  "id": "CVE-2026-48685",
  "modified": "2026-08-12T03:51:18.026997928Z",
  "published": "2026-05-26T00:00:00Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/pavel-odintsov/fastnetmon/blob/master/src/bgp_protocol.hpp"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48685.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48685"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/pavel-odintsov/fastnetmon"
    },
    {
      "type": "ARTICLE",
      "url": "https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48685-bgp-extended-length"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}