CVE-2026-18691: critical vulnerability in MongoDB Server
Improper Authentication in MongoDB Intra-Cluster Connections Allows Credential Exposure
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9epss 0.4%
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.
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
Affected products
MongoDB · MongoDB ServerRelated CVEs — MongoDB Server
In the same product, most dangerous first.
CVE-2026-18692HIGHUse-After-Free in MongoDB Timeseries Bucket Handling Leads to Denial of Service and Potential Remote Code ExecutionEPSS 0.6%CVE-2026-82071HIGHInsufficient Validation of Storage Engine Configuration Options in MongoDB Server Leads to Out-of-Bounds WriteEPSS 0.5%CVE-2026-82061HIGHUse-After-Free in MongoDB Server Query Execution Memory Tracking Subsystem Leads to Denial of ServiceEPSS 0.5%CVE-2026-82075HIGHUncontrolled Resource Consumption in MongoDB Sharded Cluster Router Allows Unauthenticated Denial of ServiceEPSS 0.5%CVE-2026-82064HIGHUnauthenticated Denial of Service in MongoDB Server via Assertion Failure in Read Concern Processing on Replica Set MembersEPSS 0.5%CVE-2026-82067CRITICALImproper Case Sensitivity Handling in MongoDB Server Configuration Validation May Cause Authorization to Remain Disabled at StartupEPSS 0.5%