---
id: CVE-2026-106438
title: >-
  An incorrect calculation in Decimal128 string parsing in the MongoDB C Driver
  can accept certain over-precision inputs containing leading zeros instead of
  rejecting them
summary: >-
  An incorrect calculation in Decimal128 string parsing in the MongoDB C Driver
  can accept certain over-precision inputs containing leading zeros instead of
  rejecting them. This produces a value different from the supplied text. An
  actor w…
severity: medium
cvss: 4
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'
cwe:
  - CWE-682
published: '2026-10-08'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T20:49:23.240'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-106438'
references:
  - url: 'https://jira.mongodb.org/browse/CDRIVER-6419'
    label: cna@mongodb.com
tags:
  - nvd
ingestedAt: '2026-10-08T20:06:22.184Z'
---

## Overview

An incorrect calculation in Decimal128 string parsing in the MongoDB C Driver can accept certain over-precision inputs containing leading zeros instead of rejecting them. This produces a value different from the supplied text. An actor who can provide a decimal string to an embedding application, including through Extended JSON parsing, can cause the application to store or use an incorrect numeric value.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.