MongoDB C Driver up to 1.30.8/2.5.1 JSON Parsing missing initialization

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.2$0-$5k1.30

Summaryinfo

A vulnerability was found in MongoDB C Driver up to 1.30.8/2.5.1. It has been rated as problematic. This affects an unknown function of the component JSON Parsing. This manipulation causes missing initialization. This vulnerability is handled as CVE-2026-84963. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability has been found in MongoDB C Driver up to 1.30.8/2.5.1 and classified as problematic. Affected by this vulnerability is an unknown function of the component JSON Parsing. The manipulation with an unknown input leads to a missing initialization vulnerability. The CWE definition for the vulnerability is CWE-456. The product does not initialize critical variables, which causes the execution environment to use unexpected values. As an impact it is known to affect integrity. The summary by CVE is:

An incorrect numeric conversion in the JSON parsing component of the MongoDB C Driver's BSON library may cause an unusually large text value to be silently shortened, or the corresponding field to be omitted, while the parsing operation still reports success and returns no error. An unauthenticated party who can supply the input processed by an application that uses this component may cause that application to hold data that does not match what was submitted, which may result in unintended alteration of data.

The advisory is shared at jira.mongodb.org. This vulnerability is known as CVE-2026-84963 since 09/02/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available.

Upgrading to version 1.30.9 or 2.5.2 eliminates this vulnerability.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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: 5.3
VulDB Meta Temp Score: 5.2

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

CNA Base Score: 5.3
CNA Vector (mongodb): 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

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

Exploitinginfo

Class: Missing initialization
CWE: CWE-456 / CWE-453
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

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

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

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-2026-84963 (🔒)
GCVE (CVE): GCVE-0-2026-84963
GCVE (VulDB): GCVE-100-398461

Entryinfo

Created: 09/03/2026 17:41
Changes: 09/03/2026 17:41 (76)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you want to use VulDB in your project?

Use the official API to access entries easily!