MongoDB BI Connector ODBC driver may write outside an allocated buffer when retrieving large floating point values as character data

{
  "id": "440daa5c6f7d97cf1298f9591ac2915ff94b3955d064331e4e6265f4e104a8c7",
  "url": "https://osv.dev/vulnerability/CVE-2026-18888",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "MongoDB BI Connector ODBC driver may write outside an allocated buffer when retrieving large floating point values as character data",
    "summary": "The MongoDB BI Connector ODBC Driver converts floating point column values into text without checking that the result fits within the destination buffer. When an application reads a sufficiently large floating point value as text, the driver may write beyond the end of that buffer and corrupt adjacent memory. A user who can store data in a collection read through the BI Connector could use this to crash the application performing the read.",
    "evidence": "osv:CVE-2026-18888",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-18888",
      "aliases": [
        "CVE-2026-18888"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/mongodb/mongo-bi-connector-odbc-driver",
              "type": "GIT",
              "events": [
                {
                  "introduced": "f68c45f988f49a9db4b8cc6be90f3e33de1ddd8f"
                },
                {
                  "fixed": "6c875f477f3c6b8f6b5620b80fd74f36678f3651"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "1.0.0"
                      },
                      {
                        "fixed": "1.4.9"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "fixed": "6c875f477f3c6b8f6b5620b80fd74f36678f3651"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v1.4.9"
                  },
                  {
                    "cpe": "cpe:2.3:a:mongodb:bi_connector_odbc_driver:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "1.0.0"
                      },
                      {
                        "fixed": "1.4.9"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.4.8",
            "v1.4.7",
            "v1.4.6",
            "v1.4.6-beta",
            "v1.4.5",
            "v1.4.4",
            "v1.4.3",
            "v1.4.2",
            "v1.4.1",
            "v1.4.0",
            "v1.3.0",
            "v1.2.0",
            "v1.1.0",
            "v1.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-18888.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:37.611590677Z",
      "provider": "osv",
      "references": [
        "https://github.com/mongodb/mongo-bi-connector-odbc-driver/releases/tag/v1.4.9",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/18xxx/CVE-2026-18888.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-18888",
        "https://github.com/mongodb/mongo-bi-connector-odbc-driver"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-787"
        ],
        "cna_assigner": "mongodb",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/18xxx/CVE-2026-18888.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-18888",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 504968,
  "published_at": "2026-08-12T20:29:33.618+00:00"
}