Vulnerability in MongoDB Bi Connector

CVE-2026-81518

When mongosqld is configured with a client certificate authority file, the listener requests a client certificate during the TLS handshake but does not require one, so a client that presents no certificate is still accepted. In deployments that rely on client certificates as the sole means of identifying users, a remote party with network access to the listener can therefore establish a session and read the MongoDB data exposed through the connector.

Vulnerability class: Improper Certificate Validation

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-81518?
CVE-2026-81518 is a high-severity vulnerability in MongoDB Bi Connector, classified under Improper Certificate Validation. CVSS score: 7.5/10. Published 2026-08-28.
How severe is CVE-2026-81518?
High severity. CVSS v3 base score is 7.5 out of 10.