CVE-2026-18691: Improper Authentication in MongoDB Intra-Cluster Connections Allows Credential Exposure
MongoDB · MongoDB Server
Vendor fix available · Affected: MongoDB Server · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 29% of scored CVEs
DescriptionCVE.org
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.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- MongoDB · MongoDB Serverfrom 8.3.0 before 8.3.8; from 8.0 before 8.0.29; from 7.0 before 7.0.40
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Vendor
- MongoDB
- Published
- August 2026
CoverageNo articles yet
No CyberSIXT article names CVE-2026-18691 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.