---
id: CVE-2026-114650
title: >-
  Plaintext exposure of encrypted fields via ANSI code-page corruption of
  database name
summary: >-
  A flaw in the client-side encryption support of the MongoDB .NET/C# driver can
  cause data designated for client-side field-level encryption to be written
  without encryption. Under certain platform text-encoding configurations, an
  interna…
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N'
cvssSource: cna
cwe:
  - CWE-838
vendor: MongoDB
product: C# Driver
affected:
  - c_driver >= 2.10.0 < 3.13.0
  - mongodb.libmongocrypt_nuget_package >= 1.0.0 <= 1.12.0
published: '2026-10-22'
updated: '2026-10-22'
sourceUpdated: '2026-10-22T21:38:04.057Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-114650'
references:
  - url: 'https://jira.mongodb.org/browse/CSHARP-6180'
  - url: 'https://github.com/mongodb/mongo-csharp-driver/releases/tag/v3.13.0'
  - url: >-
      https://github.com/mongodb/mongo-csharp-driver/security/advisories/GHSA-jvpx-6w8x-h6rg
tags:
  - cve.org
ingestedAt: '2026-10-22T22:00:50.449Z'
---

## Overview

A flaw in the client-side encryption support of the MongoDB .NET/C# driver can cause data designated for client-side field-level encryption to be written without encryption. Under certain platform text-encoding configurations, an internal name conversion loses information, so the encryption layer fails to associate the operation with its configured encryption rules and the operation proceeds without an error being raised. An application user with the ability to write data through an affected application can therefore have sensitive fields persisted in plaintext, defeating the confidentiality guarantee that client-side encryption is intended to provide. No integrity or availability impact was observed.

## Affected

- `c_driver >= 2.10.0 < 3.13.0`
- `mongodb.libmongocrypt_nuget_package >= 1.0.0 <= 1.12.0`

## Remediation

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