CVE-2021-20327

mediumpriority · track · 27EPSS 0.002 · 10 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.20% (10th) EPSS

CVSS 4.3 · medium

Is it mine?

4 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · nvd · osv

EPSS · scored 2026-10-28

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

cvss

Technical severity, 0–10. One row per scoring source.

6.8

010

base score 0–10 · higher = more severe · hover a vector to decode

v2.04.3mediumAV:A/AC:M/Au:N/C:P/I:P/A:Nprimary · NVD / NIST USexploitability 5.5 · impact 4.9

v3.16.8mediumCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Nprimary · NVD / NIST USexploitability 1.6 · impact 5.2

v3.16.4mediumCVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:Nsecondary · ENISA EU

v3.16.4mediumCVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:Nsecondary · cna@mongodb.comexploitability 1.2 · impact 5.2

v3.16.8mediumCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Nsecondary · OSV

v3.16.2mediumCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-295USprimaryCWE-295US

affected products (4)

Products and version ranges known to be affected.

MongoDB Inc. MongoDB Node.js Driver mongodb-client-encryption module≤ 1.2.0enisa_euvdEU
mongodb libmongocrypt= 1.2.0nvdUScpe:2.3:a:mongodb:libmongocrypt:*:*:*:*:*:*:*:*
mongodb mongodb client encryption= 1.2.0nvdUScpe:2.3:a:mongodb:mongodb_client_encryption:*:*:*:*:*:*:*:*
npm mongodb-client-encryption1.2.0 → 1.2.1osvUSpkg:npm/mongodb-client-encryption

advisories (1)

Vendor and ecosystem advisories describing this.

GHSA-rjmf-p882-645mmongodb-client-encryption vulnerable to Improper Certificate Validation2021-04-12ghsa · osvUS
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

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd osv NVD CVE.org MITRE

published 2021-02-25modified 2026-06-17

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references (5)

External citations — patches, advisories, analysis.

scry

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