CVE-2026-81520: MongoDB BI Connector

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

A network-reachable client that has not yet authenticated can hold a MongoDB Connector for BI authentication session open indefinitely by beginning a SASL-based login exchange and then declining to complete it. Because the negotiation loop had no overall time bound and the read from the client had no deadline, each such session retains a worker, a client connection slot, and its associated backend database connections until the process is restarted. Repeated use of this behavior can consume the configured connection capacity and prevent legitimate users from establishing new sessions.

Affected products

• MongoDB BI Connector: before 2.14.31 (fixed in 2.14.31)

Published 2026-08-28. Last modified 2026-09-29.