CVE-2026-18703: MongoDB

Medium severity, CVSS 4.2. EPSS: 0.1% chance of exploitation in the next 30 days.

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.

Affected products

• MongoDB MongoDB: from 8.2.0, up to and including 8.2.12; from 8.3.0, before 8.3.8 (fixed in 8.3.8); version 9.0.0 only; version 9.1.0 only

Published 2026-08-11. Last modified 2026-09-16.