A memory-handling error in the BSON-to-JSON conversion helpers of the MongoDB C Driver can write a small number of bytes past the end of a heap buffer when a binary field is encoded and the output is cut short at a caller-configured length limit. A party who supplies the document content, with no privileges on the application that links the driver, may cause a small amount of data outside the intended buffer to be altered.
History

Thu, 03 Sep 2026 17:00:00 +0000

Type Values Removed Values Added
First Time appeared Mongodb
Mongodb c Driver
Vendors & Products Mongodb
Mongodb c Driver

Thu, 03 Sep 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 03 Sep 2026 15:00:00 +0000

Type Values Removed Values Added
Description A memory-handling error in the BSON-to-JSON conversion helpers of the MongoDB C Driver can write a small number of bytes past the end of a heap buffer when a binary field is encoded and the output is cut short at a caller-configured length limit. A party who supplies the document content, with no privileges on the application that links the driver, may cause a small amount of data outside the intended buffer to be altered.
Title Heap overflow via truncated base64 encoding of binary fields in length-limited JSON output
Weaknesses CWE-787
References
Metrics cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N'}

cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: mongodb

Published:

Updated: 2026-09-03T15:08:11.873Z

Reserved: 2026-09-02T17:58:52.742Z

Link: CVE-2026-84969

cve-icon Vulnrichment

Updated: 2026-09-03T15:08:05.082Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-03T15:17:36.250

Modified: 2026-09-03T17:52:05.570

Link: CVE-2026-84969

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-03T16:45:06Z