Incorrect authorization in MongoDB Server - CVE-2026-18703
Published: August 18, 2026
Vulnerability identifier: #VU144127
CSH Severity: Low
CVSS v4: 2.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-18703
CWE-ID: CWE-863
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to bypass authentication mechanism restrictions.
The vulnerability exists due to improper enforcement of authentication mechanism restrictions in MongoDB Server authentication handling when processing certificate-based authentication requests. A remote user can authenticate with a valid client certificate and a corresponding user account to bypass authentication mechanism restrictions.
Exploitation requires a valid client certificate and a corresponding user account, and occurs even when the server is configured to restrict authentication to other mechanisms.
Affected software
MongoDB Server
How to mitigate CVE-2026-18703
Install security update from vendor's website.
MongoDB Server - update to 8.3.8