CVE-2026-84966

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Source
https://cve.org/CVERecord?id=CVE-2026-84966
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-84966.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-84966
Downstream
Published
2026-09-03T15:00:15Z
Modified
2026-09-24T03:46:54Z
Severity
  • 5.9 (Medium) CVSS_V4 - CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
BSON element injection via NUL-embedded document keys in builder append
Details

An incorrect numeric type conversion in the BSON document building component of the MongoDB C++ Driver may cause a length value to be interpreted incorrectly. When an application supplies an extremely large, non-terminated field name to the builder, the library may read memory outside the intended buffer and terminate the calling process. No authentication is required, but the calling application must pass the oversized name in a specific form.

Database specific 
{
    "cna_assigner": "mongodb",
    "cwe_ids": [
        "CWE-681"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84966.json",
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "introduced": "3.2.0"
                },
                {
                    "fixed": "4.5.2"
                }
            ],
            "source": "AFFECTED_FIELD"
        }
    ]
}
References

Affected packages

Git / github.com/mongodb/mongo-cxx-driver

Affected ranges

Type
GIT
Repo
https://github.com/mongodb/mongo-cxx-driver
Events
Introduced
f17d4f3109b4c9609528ec824bf0d57139e2ad82
Fixed
fd256a7017f4e49f48571a3d97a630a3b8cf75bf
Database specific
Show details 
{
    "cpe": "cpe:2.3:a:mongodb:c\\+\\+_driver:*:*:*:*:*:mongodb:*:*",
    "extracted_events": [
        {
            "introduced": "3.0.0"
        },
        {
            "fixed": "4.5.2"
        }
    ],
    "source": "CPE_RANGE"
}

Affected versions

r3.*
r3.0.0
r3.0.1
r3.0.2
r3.0.3
r3.1.0
r3.1.0-rc0
r3.11.0
r3.2.0
r3.2.0-rc0
r3.2.0-rc1
r3.3.0
r3.3.0-rc0
r3.4.0
r3.5.0
r3.6.0-rc0
r3.7.0
r3.7.0-beta1
r3.8.0
r3.9.0
r4.*
r4.0.0
r4.1.0
r4.2.0
r4.3.0
r4.4.0
r4.5.0
r4.5.1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-84966.json"