{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:mongodb:c\\#_driver:*:*:*:*:*:mongodb:*:*",
            "extracted_events": [
              {
                "introduced": "2.10.0"
              },
              {
                "fixed": "3.11.1"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "569905ff5e778c38ea19d9d0392496a83e1704ed"
            },
            {
              "fixed": "682ad0faea0a03648ee2c4ca8f48c3b04f4c9ab8"
            }
          ],
          "repo": "https://github.com/mongodb/mongo-csharp-driver",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "mongodb",
    "cwe_ids": [
      "CWE-88"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81529.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "2.0.0"
          },
          {
            "fixed": "3.11.1"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "Improper neutralization of delimiters in connection-URL construction allows connection-option injection in the MongoDB C# Driver. When an application passes untrusted text into the driver's connection-URL builder and round-trips the builder back into a client configuration, the untrusted text is serialized without neutralizing the URL/option delimiters and is then re-parsed as authoritative connection options. A low-privileged user of such an application can thereby introduce or suppress security-relevant connection settings.",
  "id": "CVE-2026-81529",
  "modified": "2026-10-01T03:30:50.743278553Z",
  "published": "2026-08-27T18:32:31.650Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://jira.mongodb.org/browse/CSHARP-6171"
    },
    {
      "type": "WEB",
      "url": "https://www.nuget.org/packages/MongoDB.Driver/3.11.1"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81529.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-81529"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Connection-option injection via unescaped settings in the canonical MongoDB URL builder"
}