{
  "affected": [
    {
      "affectedData": [
        {
          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "source": "cve@mitre.org"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:pavel-odintsov:fastnetmon:*:*:*:*:community:*:*:*",
              "matchCriteriaId": "E712A01F-3AD7-4CC2-9A8B-F8C63756EBBF",
              "versionEndIncluding": "1.2.9",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    },
    {
      "lang": "es",
      "value": "FastNetMon Community Edition hasta la versi\u00f3n 1.2.9 tiene acceso a memoria fuera de l\u00edmites porque analiza incorrectamente los atributos de ruta BGP con el indicador de longitud extendida activado. En src/bgp_protocol.hpp, la funci\u00f3n parse_raw_bgp_attribute() identifica correctamente cuando extended_length_bit est\u00e1 activado y establece length_of_length_field en 2, pero luego lee solo un byte para la longitud del valor del atributo (attribute_value_length = value[2] en la l\u00ednea 173). Seg\u00fan la RFC 4271 Secci\u00f3n 4.3, cuando el bit de longitud extendida est\u00e1 activado, el campo de longitud del atributo es de dos octetos y el valor debe leerse como un entero big-endian de 16 bits de value[2] y value[3]. Como resultado, cualquier atributo de m\u00e1s de 255 bytes tiene su longitud truncada silenciosamente al byte bajo (por ejemplo, 300 bytes = 0x012C se lee como 0x2C = 44 bytes). Los 256 bytes restantes son luego malinterpretados como atributos subsiguientes, causando fallos de an\u00e1lisis en cascada y potencial acceso a memoria fuera de l\u00edmites."
    }
  ],
  "id": "CVE-2026-48685",
  "lastModified": "2026-07-24T11:10:00.170",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 3.6,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-48685",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-05-26T20:56:09.270143Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-05-26T16:16:26.570",
  "references": [
    {
      "source": "cve@mitre.org",
      "tags": [
        "Product"
      ],
      "url": "https://github.com/pavel-odintsov/fastnetmon"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Product"
      ],
      "url": "https://github.com/pavel-odintsov/fastnetmon/blob/master/src/bgp_protocol.hpp"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48685-bgp-extended-length"
    }
  ],
  "sourceIdentifier": "cve@mitre.org",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-130"
        }
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary"
    }
  ]
}