CVE-2026-81517: MongoDB Connector for BI Improper Error Handling of Log Write Failures May Cause Loss of SQL Service
An unauthenticated party able to reach the port of a MongoDB Connector for BI (mongosqld) instance may generate enough routine connection log activity to exhaust the storage backing the configured log path. When a log write or log rotation operation subsequently fails, the resulting error is not handled and the shared mongosqld process ends, ending service for all connected SQL clients. The process continues to end on startup until an operator restores available storage, and the diagnostic message explaining the condition is not recorded.
Affected Software
Event History
Frequently Asked Questions
Which deployments are exposed?
mongosqld instances whose port is reachable by unauthenticated parties are exposed if the storage backing the configured log path can be exhausted.
Does an attacker need credentials or user interaction?
No. An unauthenticated party only needs network reachability to the mongosqld port and can generate routine connection log activity.
What can be done if the service is already failing?
Restore available storage for the configured log path. The shared mongosqld process will continue to end on startup until storage is restored.
How can operators recognize this condition?
All connected SQL clients lose service when the shared mongosqld process ends, and repeated startup failures continue while storage remains unavailable. The diagnostic message explaining the condition is not recorded.