CVE-2026-18703 Auth bypass in MongoDB Server
Attackers with valid certificates can bypass disabled authentication mechanisms in MongoDB Server, undermining administrator-configured security restrictions.
- 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-2026-18703?
CVE-2026-18703 is a low-severity authentication bypass vulnerability in Mongodb Mongodb, published on 11 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
An issue in MongoDB Server could allow a party with a valid client certificate and a corresponding user account to authenticate using a certificate-based authentication method, even when an administrator has configured the server to restrict authentication to other mechanisms. This could allow authentication through a method the administrator intended to disable.
Weakness: CWE-863
Which versions are affected by CVE-2026-18703?
1 open source package ship an affected version, including mongodb. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
mongodb Bitnami | From 8.2.0 | 8.3.8, 9.0.2 |
Products include Mongodb Mongodb.
How do I fix CVE-2026-18703?
Upgrade mongodb to a fixed version for your release line: 8.3.8 or 9.0.2.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-18703 being exploited?
There is no known exploitation of CVE-2026-18703 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-2026-18703, GHSA-h22h-g2cf-r8hr, MINI-jwrf-q9gw-h6r9, MINI-mfjm-h5rw-88wv, UBUNTU-CVE-2026-18703.