Executive Summary

Node.js mongodb-client-encryption v1.2.0 fails to validate KMS server certificates, enabling MITM on privileged networks to intercept traffic and bypass client‑side field‑level encryption. The flaw is limited to this version, deprecated in Feb 2021, and does not affect workloads using CSFLE within AWS, GCP, or Azure fabrics or those not employing field‑level encryption. No CISA KEV listing yet.

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Authoritative CVE Metadata - CVSS Base Score: 6.4 (MEDIUM) - Published: 2021-02-25T17:15:28.160 - Last Modified: 2026-09-17T13:57:49.890

Original Description: A specific version of the Node.js mongodb-client-encryption module does not perform correct validation of the KMS server’s certificate. This vulnerability in combination with a privileged network position active MITM attack could result in interception of traffic between the Node.js driver and the KMS service rendering client-side field level encryption (CSFLE) ineffective. This issue was discovered during internal testing and affects mongodb-client-encryption module version 1.2.0, which was available from 2021-Jan-29 and deprecated in the NPM Registry on 2021-Feb-04. This vulnerability does not impact driver traffic payloads with CSFLE-supported key services from applications residing inside the AWS, GCP, and Azure nework fabrics due to compensating controls in these environments. This issue does not impact driver workloads that don’t use Field Level Encryption. This issue affect MongoDB Node.js Driver mongodb-client-encryption module version 1.2.0

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