{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:mongodb:c_driver:*:*:*:*:*:mongodb:*:*",
            "extracted_events": [
              {
                "introduced": "2.0.0"
              },
              {
                "fixed": "2.3.2"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "67817df0a9ed11b07e457477e6db1384da9421c4"
            },
            {
              "fixed": "76e9b7d7a2363f765a125e8015e48c7b3ff4899e"
            }
          ],
          "repo": "https://github.com/mongodb/mongo-c-driver",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "mongodb",
    "cwe_ids": [
      "CWE-303"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93394.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "2.0.0"
          },
          {
            "fixed": "2.3.2"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "A flaw in libmongoc's SCRAM authentication implementation caused the client to continue the authentication handshake and transmit the client proof even when a nonce mismatch was detected in the server's first message. An unauthorized party with a man-in-the-middle position could exploit this by injecting a crafted server-first-message containing a controlled salt and low iteration count, then capturing the resulting client proof to perform offline password cracking. This vulnerability is mitigated by TLS, which is standard in production deployments.",
  "id": "CVE-2026-93394",
  "modified": "2026-09-27T03:30:13.534685835Z",
  "published": "2026-09-17T20:31:27.875Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://jira.mongodb.org/browse/CDRIVER-6315"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93394.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-93394"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "libmongoc SCRAM client nonce-validation bypass"
}