CVE-2019-20925 Denial of service via malformed network packet
Unauthenticated attackers can cause denial of service in MongoDB Server by sending malformed network packets that trigger incorrect memory allocation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2019-20925?
CVE-2019-20925 is a high-severity denial of service vulnerability in Mongodb Mongodb, published on 24 Nov 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An unauthenticated client can trigger denial of service by issuing specially crafted wire protocol messages, which cause the message decompressor to incorrectly allocate memory. This issue affects MongoDB Server v4.2 versions prior to 4.2.1; MongoDB Server v4.0 versions prior to 4.0.13; MongoDB Server v3.6 versions prior to 3.6.15 and MongoDB Server v3.4 versions prior to 3.4.24.
Which versions are affected by CVE-2019-20925?
It affects 1 product.
Products include Mongodb Mongodb.
How do I fix CVE-2019-20925?
Upgrade to a fixed version.
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-2019-20925 being exploited?
There is no known exploitation of CVE-2019-20925 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 GHSA-q4wj-8854-jvxq, UBUNTU-CVE-2019-20925, USN-5101-1.