CVE-2021-20326 Specially crafted query may result in a denial of service of mongod
An authorized user can cause a denial of service in MongoDB Server by submitting a specially crafted find query.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-20326?
CVE-2021-20326 is a medium-severity denial of service vulnerability in Mongodb Mongodb, published on 30 Apr 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2021-20326?
1 open source package ship an affected version, including mongodb. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
mongodb Bitnami | From 4.4.0 | 4.4.4 |
Products include Mongodb Mongodb.
How do I fix CVE-2021-20326?
Upgrade mongodb to 4.4.4 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-20326 being exploited?
There is no known exploitation of CVE-2021-20326 in the wild and no public exploit code.
Other vulnerabilities in Mongodb Mongodb
- CVE-2025-14847 MongoDB and MongoDB Server Improper Handling of Length Parameter Inconsistency
- CVE-2026-82067 Auth bypass in MongoDB Server
- CVE-2026-13072 MongoDB Improper Input Validation in Compute Mode External Data Processing Leading to Memory Corruption
- CVE-2017-15535 Denial of service in n/a
- CVE-2026-18691 Improper Authentication in MongoDB Intra-Cluster Connections Allows Credential Exposure
Sources
Also known as BIT-mongodb-2021-20326, GHSA-vqmx-64jh-5r2h.