What is CVE-2021-20329?

CVE-2021-20329 is a medium-severity vulnerability in MongoDB Go Driver, classified under CWE-1287. CVSS score: 6.8/10. Published 2021-06-10.

How severe is CVE-2021-20329?

Medium severity. CVSS v3 base score is 6.8 out of 10.

Improper input validation in MongoDB Go Driver

CVE-2021-20329

Specific cstrings input may not be properly validated in the MongoDB Go Driver when marshalling Go objects into BSON. A malicious user could use a Go object with specific string to potentially inject additional fields into marshalled documents. This issue affects all MongoDB GO Drivers prior to and including 1.5.0.

Published 2021-06-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.009 (59.2th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 59.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.009 · change: -0.000

Affected products

MongoDB Go Driver
MongoDB Inc. Go Driver — versions 1.0

Weakness classification (CWE)

References

github.com/mongodb/mongo-go-driver/releases/tag/v1.5.1 (Third Party Advisory, Release Notes)

Frequently asked questions

What is CVE-2021-20329?: CVE-2021-20329 is a medium-severity vulnerability in MongoDB Go Driver, classified under CWE-1287. CVSS score: 6.8/10. Published 2021-06-10.
How severe is CVE-2021-20329?: Medium severity. CVSS v3 base score is 6.8 out of 10.