What is CVE-2019-2393?

CVE-2019-2393 is a medium-severity vulnerability in MongoDB, classified under Use After Free. CVSS score: 6.5/10. Published 2020-11-23.

How severe is CVE-2019-2393?

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

Use After Free in MongoDB

CVE-2019-2393

A user authorized to perform database queries may trigger denial of service by issuing specially crafted queries, which use $lookup and collations. This issue affects MongoDB Server v4.2 versions prior to 4.2.1; MongoDB Server v4.0 versions prior to 4.0.13 and MongoDB Server v3.6 versions prior to 3.6.15.

Vulnerability class: Use-After-Free

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 (68.3th percentile), scored 2026-10-03.

Low probability of exploitation in the next 30 days, but still tracked. 68th percentile — 68.3% 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, 4.2

Weakness classification (CWE)

CWE-416 — Use After Free

References

jira.mongodb.org/browse/SERVER-43350 (Issue Tracking, Vendor Advisory)

Frequently asked questions

What is CVE-2019-2393?: CVE-2019-2393 is a medium-severity vulnerability in MongoDB, classified under Use After Free. CVSS score: 6.5/10. Published 2020-11-23.
How severe is CVE-2019-2393?: Medium severity. CVSS v3 base score is 6.5 out of 10.