CVE-2026-81517: high-severity vulnerability in MongoDB BI Connector
MongoDB Connector for BI Improper Error Handling of Log Write Failures May Cause Loss of SQL Service
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.7epss 0.5%
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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Affected products
MongoDB · BI ConnectorRelated CVEs — MongoDB BI Connector
In the same product, most dangerous first.
CVE-2026-75159HIGHMongoDB BI Connector Improper Memory Handling During Failed Kerberos Authentication May Cause Process TerminationEPSS 0.5%CVE-2026-81490HIGHMongoDB Connector for BI Improper Error Handling During Schema Sampling May Cause Loss of SQL ServiceEPSS 0.5%CVE-2026-77586HIGHMongoDB Connector for BI Unescaped Object Names in Generated SHOW CREATE OutputEPSS 0.4%CVE-2026-81520HIGHMongoDB Connector for BI Unbounded Authentication Negotiation Leading to Connection ExhaustionEPSS 0.4%CVE-2026-77184MEDIUMMongoDB Connector for BI Incomplete Escaping of Stored Metadata in Generated SHOW CREATE OutputEPSS 0.3%CVE-2026-81518HIGHBI Connector Optional Client Certificate Verification Allows Unauthenticated ConnectionsEPSS 0.3%