CVE-2026-84970
Heap over-read or silent misparse via 32-bit truncation of JSON length in BSON JSON parser
CVSS Score
6.2
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-681 |
| Vendor | mongodb |
| Product | c++ driver |
| Ecosystems | |
| Industries | Technology |
| Published | Sep 3, 2026 |
| Last Updated | Sep 3, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H Attack Vector
Local
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
High
Affected Versions
MongoDB / C++ Driver
3.2.0 < 4.5.2