CVE-2026-84969
Heap overflow via truncated base64 encoding of binary fields in length-limited JSON output
CVSS Score
3.7
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-787 |
| 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:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None
Affected Versions
MongoDB / C Driver
1.30.0 < 1.30.9 2.0.0 < 2.5.2