CVE-2026-84966
CVE-2026-84966
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.
CVSS v3 metric
CVSS v3 base score 5.1 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-84966?
- CVE-2026-84966 is a medium-severity vulnerability, classified under Incorrect Conversion between Numeric Types. CVSS score: 5.1/10. Published 2026-09-03.
- How severe is CVE-2026-84966?
- Medium severity. CVSS v3 base score is 5.1 out of 10.