---
id: CVE-2026-114655
title: >-
  KMS request injection via unsanitized key vault and provider values in
  libmongocrypt
summary: >-
  libmongocrypt builds requests to external key management services (AWS, Azure
  and GCP) by inserting values from key vault documents, KMS provider
  configuration and KMS responses into request lines, headers and signed request
  bodies witho…
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-74
vendor: MongoDB
product: libmongocrypt
affected:
  - libmongocrypt >= 1.0.0 < 1.21.1
published: '2026-10-22'
updated: '2026-10-22'
sourceUpdated: '2026-10-22T20:38:26.441Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-114655'
references:
  - url: 'https://jira.mongodb.org/browse/MONGOCRYPT-963'
  - url: 'https://github.com/mongodb/libmongocrypt/releases/tag/1.21.1'
  - url: >-
      https://github.com/mongodb/libmongocrypt/security/advisories/GHSA-7mvq-mg47-m88j
tags:
  - cve.org
ingestedAt: '2026-10-22T22:00:50.420Z'
---

## Overview

libmongocrypt builds requests to external key management services (AWS, Azure and GCP) by inserting values from key vault documents, KMS provider configuration and KMS responses into request lines, headers and signed request bodies without validating or encoding them for each context. A user with write access to the key vault collection can alter the structure of these requests, including adding members to request bodies and token claims that the library then signs with the application's credentials. This may result in key management operations being performed with parameters the application did not intend.

## Affected

- `libmongocrypt >= 1.0.0 < 1.21.1`

## Remediation

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