---
id: CVE-2026-18687
title: >-
  MongoDB Server's handling of a Queryable Encryption maintenance operation did
  not properly validate certain request parameters against the collection's
  encrypted field configuration before use
summary: >-
  MongoDB Server's handling of a Queryable Encryption maintenance operation did
  not properly validate certain request parameters against the collection's
  encrypted field configuration before use. An authenticated user with readWrite
  privil…
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H'
cwe:
  - CWE-191
vendor: mongodb
product: mongodb
affected:
  - 'mongodb >= 8.0.0, < 8.0.29'
  - 'mongodb >= 8.2.0, <= 8.2.12'
  - 'mongodb >= 8.3.0, < 8.3.8'
  - mongodb = 9.0.0
  - mongodb = 9.1.0
patched:
  - mongodb 8.3.8
published: '2026-08-11'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T15:14:07.103'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-18687'
references:
  - url: 'https://jira.mongodb.org/browse/SERVER-130628'
    label: cna@mongodb.com
tags:
  - nvd
epss: 0.00234
epssPercentile: 0.12826
ingestedAt: '2026-08-29T19:41:15.402Z'
---

## Overview

MongoDB Server's handling of a Queryable Encryption maintenance operation did not properly validate certain request parameters against the collection's encrypted field configuration before use. An authenticated user with readWrite privileges could submit a specially formed request that leads to a server crash or excessive internal writes, resulting in resource exhaustion and corruption of encrypted index data.

## Affected

- `mongodb >= 8.0.0, < 8.0.29`
- `mongodb >= 8.2.0, <= 8.2.12`
- `mongodb >= 8.3.0, < 8.3.8`
- `mongodb = 9.0.0`
- `mongodb = 9.1.0`

## Remediation

Upgrade past the affected range:

- `mongodb 8.3.8`