Quick answers
- Is CVE-2026-81518 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-81518 being exploited in the wild.
- How severe is CVE-2026-81518?
- High severity, with a CVSS score of 7.5, published 28 August 2026.
- Which products and versions are affected?
- MongoDB Connector for BI <UNKNOWN>.
- Is there a fix for CVE-2026-81518?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-81518 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-81518?
- Check whether you run MongoDB Connector for BI at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability is an authentication bypass in the TLS handshake logic of mongosqld. When a client certificate authority file is configured, the listener requests a client certificate during the TLS handshake but fails to enforce its presence, allowing connections with no certificate to succeed. The root cause is improper validation of client certificate requirements during the TLS handshake. The attack vector is network-based with no authentication required—an unauthenticated attacker on the network can connect and read exposed MongoDB data. A patch addressing this validation enforcement is available in the MongoDB BI Connector release notes.
Affected products
- MongoDB Connector for BI <UNKNOWN>
Timeline
- 2026-08-28: disclosed
- 2026-08-28: advisory: CVE-2026-81518 assigned