CVE-2026-18691

An issue in MongoDB Server's intra-cluster connection setup could allow a party with suitable network access to influence which authentication mechanism is used when one replica set member connects to another. Under certain conditions, this could cause the cluster's shared internal credential to be transmitted in a less-protected form, potentially allowing that credential to be recovered. If recovered, the credential could be used to authenticate as the internal superuser to nodes in the deployment.
References
Link Resource
https://jira.mongodb.org/browse/SERVER-130264 Vendor Advisory Issue Tracking
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:mongodb:mongodb:*:*:*:*:*:*:*:*
cpe:2.3:a:mongodb:mongodb:*:*:*:*:*:*:*:*
cpe:2.3:a:mongodb:mongodb:*:*:*:*:*:*:*:*
cpe:2.3:a:mongodb:mongodb:*:*:*:*:*:*:*:*
cpe:2.3:a:mongodb:mongodb:9.0.0:alpha0:*:*:-:-:*:*
cpe:2.3:a:mongodb:mongodb:9.0.0:alpha1:*:*:-:-:*:*
cpe:2.3:a:mongodb:mongodb:9.1.0:alpha0:*:*:-:-:*:*

History

23 Oct 2026, 21:10

Type Values Removed Values Added
Summary
  • (es) Un problema en la configuración de conexión intra-clúster del servidor MongoDB podría permitir a una parte con acceso de red adecuado influir en qué mecanismo de autenticación se utiliza cuyo un miembro del conjunto de réplicas se conecta a otro. Bajo ciertas condiciones, esto podría causar que la credencial interna compartida del clúster se transmita en una forma menos protegida, permitiendo potencialmente que esa credencial sea recuperada. Si se recupera, la credencial podría usarse para autenticarse como el superusuario interno en los nodos de la implementación.

16 Sep 2026, 15:16

Type Values Removed Values Added
First Time Mongodb
Mongodb mongodb
CPE cpe:2.3:a:mongodb:mongodb:9.0.0:alpha1:*:*:-:-:*:*
cpe:2.3:a:mongodb:mongodb:9.1.0:alpha0:*:*:-:-:*:*
cpe:2.3:a:mongodb:mongodb:9.0.0:alpha0:*:*:-:-:*:*
cpe:2.3:a:mongodb:mongodb:*:*:*:*:*:*:*:*
References () https://jira.mongodb.org/browse/SERVER-130264 - () https://jira.mongodb.org/browse/SERVER-130264 - Vendor Advisory, Issue Tracking

Information

Published : 2026-08-11 19:17

Updated : 2026-10-23 21:10


NVD link : CVE-2026-18691

Mitre link : CVE-2026-18691

CVE.ORG link : CVE-2026-18691


JSON object : View

Products Affected

mongodb

  • mongodb
CWE
CWE-757

Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')