Advisoriesby IbisMongoDBCVE-2026-18691
An issue in MongoDB Server's intra-cluster connection setup
Fix: upgrade to 8.3.8 or later (3 fixed versions below)
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 versions
| Package | Affected | Fixed in |
|---|---|---|
| MongoDB Server Product | >= 8.3.0, < 8.3.8 | 8.3.8 |
| >= 8.0, < 8.0.29 | 8.0.29 | |
| >= 7.0, < 7.0.40 | 7.0.40 |
Details and references
- CVSS 4.0
- 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Severity from
- the vendor (its own CVE record or advisory)
- Weakness
- CWE-757