Vulnerability Details CVE-2026-84970
A numeric truncation weakness exists in the JSON parsing component of the MongoDB C++ Driver's BSON library. An actor who controls the text that an embedding application hands to the library's public JSON parsing interface, when that text is very large, can cause the library to read memory beyond the supplied buffer and return it to the caller, to silently accept only part of the input as a complete document, or to terminate the process. No MongoDB server, credentials, or non-default configuration is required; the effect is confined to the process that uses the library.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.001
EPSS Ranking 0.9%
CVSS Severity
CVSS v3 Score 6.2
References