CVE-2026-106437

Out-of-bounds read and write via undersized BSON buffer reservation in MongoDB C Driver

HIGH
7.4
CVSS Score
Published: October 8, 2026 at 06:42 PM UTC
Updated: October 27, 2026 at 07:56 PM UTC
1 product affected across 1 vendorC++ Driver

Using C Driver by MongoDB?

Get instant alerts when new vulnerabilities affect C Driver - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH7.4
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

Description

The BSON buffer-reservation API in the MongoDB C Driver can record a length smaller than the five-byte BSON minimum. Later append or comparison operations can underflow unsigned length calculations and read or write outside the document buffer. An actor who can influence the length supplied by an embedding application can cause the application to terminate or read or corrupt adjacent process memory. Reaching this issue requires the application to pass an undersized value to bson_reserve_buffer and then perform an affected operation.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

1.4.0 ≤ v < 1.30.132.0.0 ≤ v < 2.5.61.4.02.0.0

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

Vendor AdvisoryIssue Tracking
Source: cverecord
https://jira.mongodb.org/browse/CDRIVER-6423

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-191

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card