MongoDB C Driver up to 1.30.8/2.5.1 BSON-to-JSON Conversion Helpers heap-based overflow

CVSS Meta Temp Score
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CTI Interest Score
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4.4$0-$5k0.92+

Summaryinfo

A vulnerability described as problematic has been identified in MongoDB C Driver up to 1.30.8/2.5.1. Affected is an unknown function of the component BSON-to-JSON Conversion Helpers. Executing a manipulation can lead to heap-based overflow. This vulnerability is tracked as CVE-2026-84969. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability has been found in MongoDB C Driver up to 1.30.8/2.5.1 and classified as problematic. This vulnerability affects an unknown code block of the component BSON-to-JSON Conversion Helpers. The manipulation with an unknown input leads to a heap-based overflow vulnerability. The CWE definition for the vulnerability is CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). As an impact it is known to affect integrity. CVE summarizes:

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.

The advisory is shared for download at jira.mongodb.org. This vulnerability was named CVE-2026-84969 since 09/02/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available.

Upgrading to version 1.30.9 or 2.5.2 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Vendor

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 4.5
VulDB Meta Temp Score: 4.4

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 3.7
CNA Vector (mongodb): 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Heap-based overflow
CWE: CWE-122 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: C Driver 1.30.9/2.5.2

Timelineinfo

09/02/2026 CVE reserved
09/03/2026 +1 days Advisory disclosed
09/03/2026 +0 days VulDB entry created
09/03/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: jira.mongodb.org
Status: Confirmed

CVE: CVE-2026-84969 (🔒)
GCVE (CVE): GCVE-0-2026-84969
GCVE (VulDB): GCVE-100-398452

Entryinfo

Created: 09/03/2026 17:23
Changes: 09/03/2026 17:23 (76)
Complete: 🔍
Cache ID: 216::103

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