What is CVE-2021-20326?

CVE-2021-20326 is a medium-severity vulnerability in MongoDB, classified under Improper Input Validation. CVSS score: 6.5/10. Published 2021-04-30.

How severe is CVE-2021-20326?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Improper input validation in MongoDB

CVE-2021-20326

A user authorized to performing a specific type of find query may trigger a denial of service. This issue affects MongoDB Server v4.4 versions prior to 4.4.4.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2021-04-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.009 (59.7th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 60th percentile — 59.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

MongoDB
MongoDB Inc. Server — versions 4.4

Weakness classification (CWE)

References

jira.mongodb.org/browse/SERVER-53929 (Patch, Issue Tracking, Vendor Advisory)

Frequently asked questions

What is CVE-2021-20326?: CVE-2021-20326 is a medium-severity vulnerability in MongoDB, classified under Improper Input Validation. CVSS score: 6.5/10. Published 2021-04-30.
How severe is CVE-2021-20326?: Medium severity. CVSS v3 base score is 6.5 out of 10.