Security advisory

{
  "id": "57a15a99b420e4e55701813a315fa409babdae512f8252abbcd58303e9542b7b",
  "url": "https://osv.dev/vulnerability/CVE-2026-48682",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2026-48682",
    "summary": "FastNetMon Community Edition through 1.2.9 contains an out-of-bounds read in the IPv4 packet parser. In src/simple_packet_parser_ng.cpp, after validating that the packet contains at least sizeof(ipv4_header_t) bytes (20 bytes), the code advances the local_pointer by '4 * ipv4_header->get_ihl()' (line 164) without validating that (a) IHL >= 5 (the minimum valid value per RFC 791), or (b) 4 * IHL bytes are actually available in the packet. The IHL field is 4 bits, allowing values 0-15, so the advance can be 0-60 bytes. An IHL value of 15 with only 20 bytes validated causes a 40-byte over-read. An IHL of 0-4 causes the pointer to not advance past the IP header, resulting in the TCP/UDP header being parsed from IP header data (type confusion). This vulnerability is reachable via any packet capture interface.",
    "evidence": "osv:CVE-2026-48682",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-48682",
      "aliases": [
        "CVE-2026-48682"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/pavel-odintsov/fastnetmon",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "394fbe06d112f9609d3d1cb10d60cbf98347c96a"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "1.2.9"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.2.9",
            "v1.2.8",
            "v1.2.7",
            "v1.2.6",
            "v1.2.5",
            "v1.2.4",
            "v1.2.3",
            "v1.2.2",
            "v1.2.1",
            "v1.2.0",
            "v1.1.9",
            "v1.1.8",
            "v1.1.7",
            "v1.1.6",
            "v1.1.5",
            "v1.1.4",
            "v1.1.3",
            "v1.1.2",
            "v1.1.0",
            "v1.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-48682.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:38.878294598Z",
      "provider": "osv",
      "references": [
        "https://github.com/pavel-odintsov/fastnetmon/blob/master/src/simple_packet_parser_ng.cpp",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48682.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-48682",
        "https://github.com/pavel-odintsov/fastnetmon",
        "https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48682-ipv4-parser-oob"
      ],
      "provider_metadata": {
        "cna_assigner": "mitre",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48682.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-48682",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 506189,
  "published_at": "2026-06-02T00:00:00+00:00"
}