What is CVE-2018-20805?

CVE-2018-20805 is a medium-severity vulnerability in MongoDB, classified under Excessive Iteration. CVSS score: 6.5/10. Published 2020-11-23.

How severe is CVE-2018-20805?

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

Vulnerability in MongoDB

CVE-2018-20805

A user authorized to perform database queries may trigger denial of service by issuing specially crafted queries, which perform an $elemMatch . This issue affects MongoDB Server v4.0 versions prior to 4.0.5 and MongoDB Server v3.6 versions prior to 3.6.10.

Published 2020-11-23 · 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: 0.012 (68.2th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 68th percentile — 68.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000

Affected products

MongoDB
MongoDB Inc. Server — versions 3.6, 4.0

Weakness classification (CWE)

CWE-834 — Excessive Iteration

References

jira.mongodb.org/browse/SERVER-38164 (Issue Tracking, Vendor Advisory)

Frequently asked questions

What is CVE-2018-20805?: CVE-2018-20805 is a medium-severity vulnerability in MongoDB, classified under Excessive Iteration. CVSS score: 6.5/10. Published 2020-11-23.
How severe is CVE-2018-20805?: Medium severity. CVSS v3 base score is 6.5 out of 10.