Heap corruption via OCSP request double free from crafted multi-URL certificate in TLS client

{
  "id": "92a16b4fe068a9b43a7053d2b3b9ffd5e410673552a2267e5e2f9369cf1fc2d8",
  "url": "https://osv.dev/vulnerability/CVE-2026-84964",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Heap corruption via OCSP request double free from crafted multi-URL certificate in TLS client",
    "summary": "A double free in the OpenSSL-based TLS certificate revocation checking path of the MongoDB C Driver can be reached by a TLS endpoint that the client already trusts. During the handshake, specially formed certificate data can cause the same heap object to be released twice. An unauthenticated party acting as the trusted endpoint may cause the connecting client application to terminate unexpectedly.",
    "evidence": "osv:CVE-2026-84964",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-84964",
      "aliases": [
        "CVE-2026-84964"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/mongodb/mongo-c-driver",
              "type": "GIT",
              "events": [
                {
                  "introduced": "b51d1e458affc441ca9255985fec56a89270f90c"
                },
                {
                  "fixed": "f64476433230847fb0f43afaeb7be048eb817f8b"
                },
                {
                  "introduced": "67817df0a9ed11b07e457477e6db1384da9421c4"
                },
                {
                  "fixed": "52ffca1e649b597c51162b5b3b37f057b73b059d"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:mongodb:c_driver:*:*:*:*:*:mongodb:*:*",
                    "range": [
                      {
                        "introduced": "1.17.0"
                      },
                      {
                        "fixed": "1.30.9"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:mongodb:c_driver:*:*:*:*:*:mongodb:*:*",
                    "range": [
                      {
                        "introduced": "2.0.0"
                      },
                      {
                        "fixed": "2.5.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-84964.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:35.951101664Z",
      "provider": "osv",
      "references": [
        "https://jira.mongodb.org/browse/CDRIVER-6409",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84964.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-84964"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-415"
        ],
        "cna_assigner": "mongodb",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "1.17.0"
                  },
                  {
                    "fixed": "1.30.9"
                  },
                  {
                    "introduced": "2.0.0"
                  },
                  {
                    "fixed": "2.5.2"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84964.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-84964",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 503464,
  "published_at": "2026-09-03T15:02:20.836+00:00"
}