CVE-2018-20802

Publication date 23 November 2020

Last updated 27 February 2026

Ubuntu priority

Cvss 3 Severity Score

Description

A user authorized to perform database queries may trigger denial of service by issuing specially crafted queries with compound indexes affecting QueryPlanner. This issue affects MongoDB Server v3.6 versions prior to 3.6.9 and MongoDB Server v4.0 versions prior to 4.0.3.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
mongodb	25.10 questing	Not in release
	25.04 plucky	Not in release
	24.10 oracular	Not in release
	24.04 LTS noble	Not in release
	23.10 mantic	Not in release
	23.04 lunar	Not in release
	22.10 kinetic	Not in release
	22.04 LTS jammy	Not in release
	21.10 impish	Not in release
	21.04 hirsute	Not in release
	20.10 groovy	Not in release
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Fixed 1:3.6.3-0ubuntu1.4+esm1
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected

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Notes

john-breton

Fortunately the patch was released a month before the switch to SSPL, so it is still fair for us to use.

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
mongodb	Upstream: 2b4634b

Severity score breakdown

Parameter	Value
Base score	6.5 · Medium
Attack vector	Network
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

USN-8064-1
MongoDB vulnerabilities
25 February 2026