What’s Vulnerable › Vulnerabilities
CVE-2026-84966: BSON element injection via NUL-embedded document keys in builder append
- Severity: medium (CVSS 5.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.1% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-09-03 · updated 2026-09-22
- Weakness: CWE-681
Description
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.
Affected products
- MongoDB C++ Driver: from 3.0.0 before 4.5.2 — fixed in 4.5.2
How to fix
Upgrade to a fixed version: MongoDB C++ Driver 4.5.2. Check the vendor advisory for mitigations.
References
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