CVE-2026-84966

EUVD-2026-70511
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
mongodbCNA
5.1 MEDIUM
LOCAL
HIGH
NONE
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
mongodbc_driver
3.2.0 ≤
𝑥
< 4.5.2
CNA