bson_validate may skip validation when processing certain inputs

{
  "id": "1c039bf754c4be6a594736053f63ca25d0b6039f25417a63921458ea5449c291",
  "url": "https://osv.dev/vulnerability/CVE-2026-6231",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "bson_validate may skip validation when processing certain inputs",
    "summary": "The bson_validate function may return early on specific inputs and incorrectly report success. This behavior could result in skipping validation for BSON data, allowing malformed or invalid UTF-8 sequences to bypass validation and be processed incorrectly. The issue may affect applications that rely on these functions to validate untrusted BSON data before further processing. This issue affects MongoDB C Driver versions prior to 1.30.5, MongoDB C Driver version 2.0.0 and MongoDB C Driver version 2.0.1",
    "evidence": "osv:CVE-2026-6231",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-6231",
      "aliases": [
        "CVE-2026-6231"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/mongodb/mongo-c-driver",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "252989c310f7a326230f66311630ba259e34e4b3"
                },
                {
                  "introduced": "67817df0a9ed11b07e457477e6db1384da9421c4"
                },
                {
                  "fixed": "d94ed7a504c227fa8a69d979abff485174f3cf5d"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:mongodb:c_driver:*:*:*:*:*:mongodb:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.30.5"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:mongodb:c_driver:*:*:*:*:*:mongodb:*:*",
                    "range": [
                      {
                        "introduced": "2.0.0"
                      },
                      {
                        "fixed": "2.0.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "1.30.4",
            "2.0.1",
            "1.30.3",
            "2.0.0",
            "1.30.2",
            "1.30.1",
            "1.30.0",
            "1.11.0",
            "1.9.0-rc1",
            "1.9.0-rc0",
            "1.7.0-rc0",
            "1.6.0",
            "1.6.0-rc0",
            "1.5.0-rc4",
            "1.5.0-rc3",
            "1.5.0-rc2",
            "1.5.0-rc1",
            "1.5.0-rc0",
            "1.4.0-beta1",
            "1.3.0",
            "1.3.0-rc0",
            "1.1.11",
            "1.1.10",
            "1.1.9",
            "1.1.8",
            "1.1.7",
            "1.1.6",
            "1.1.5",
            "1.1.4",
            "1.1.2",
            "1.1.0",
            "1.1.0-rc0",
            "1.0.2",
            "1.0.0",
            "0.98.2",
            "0.98.0",
            "0.96.4",
            "0.96.0",
            "0.94.2",
            "0.94.0",
            "0.92.2",
            "0.92.0",
            "0.90.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6231.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:27.662854083Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6231.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-6231",
        "https://jira.mongodb.org/browse/CDRIVER-6017"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-20"
        ],
        "cna_assigner": "mongodb",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "1.0"
                  },
                  {
                    "fixed": "1.30.5"
                  },
                  {
                    "introduced": "2.0"
                  },
                  {
                    "fixed": "2.0.2"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6231.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-6231",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 494432,
  "published_at": "2026-04-13T15:31:55.735+00:00"
}