MOOS core-moos through 10.4.0 MOOSDB Pre-Authentication Heap Overflow via Negative Packet Length

{
  "id": "ce4e7b9f4650aa61d3e1460b1611c38c00daee8190de044790b480159e2f29b2",
  "url": "https://osv.dev/vulnerability/CVE-2026-85440",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "MOOS core-moos through 10.4.0 MOOSDB Pre-Authentication Heap Overflow via Negative Packet Length",
    "summary": "MOOS core-moos through 10.4.0 contains a pre-authentication heap overflow vulnerability in MOOSCommPkt packet handling that allows remote attackers to write arbitrary data by declaring a negative packet length. Attackers can exploit the signed integer check in InflateTo() and negative size conversion in recv() to overflow a four-byte heap buffer during the HandShake phase before authentication.",
    "evidence": "osv:CVE-2026-85440",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-85440",
      "aliases": [
        "CVE-2026-85440"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/themoos/core-moos",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "19d06a9aefc910b0504c2c8589b1403f3b6e77a8"
                },
                {
                  "fixed": "96c49c5cdda6e07ee734a5324e8d25ba5a7f2d7a"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:themoos:core-moos:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "10.4.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "96c49c5cdda6e07ee734a5324e8d25ba5a7f2d7a"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v10.0.4-alpha",
            "10.0.3-devel-candidate",
            "10.0.2-devel",
            "10.0.1-devel",
            "PreProfilingmerge",
            "IvPCompatibility"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-85440.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:34.980535174Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/85xxx/CVE-2026-85440.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-85440",
        "https://www.vulncheck.com/advisories/moos-core-moos-through-10.4.0-moosdb-pre-authentication-heap-overflow-via-negative-packet-length",
        "https://github.com/themoos/core-moos/commit/96c49c5cdda6e07ee734a5324e8d25ba5a7f2d7a",
        "https://github.com/themoos/core-moos/pull/82",
        "https://github.com/themoos/core-moos",
        "https://github.com/themoos/core-moos/blob/ec9c77c68fcbdef8f5e4c60fe243acd223433f0c/Core/libMOOS/Comms/MOOSCommPkt.cpp#L67"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-787"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/85xxx/CVE-2026-85440.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-85440",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 502267,
  "published_at": "2026-09-03T22:38:31.246+00:00"
}