# CVE-2026-81517: MongoDB Connector for BI Improper Error Handling of Log Write Failures May Cause Loss of SQL Service

> CVE-2026-81517: MongoDB Connector for BI Improper Error Handling of Log Write Failures May Cause Loss of SQL Service. CVSS 7.5 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-81517
Last updated: 2026-09-29T19:14:57Z

- Published: 2026-08-28 20:14 UTC · Updated: 2026-09-29 19:14 UTC · Assigner: mongodb
- CVSS: 7.5 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS: 0.46%, 40th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-248

## Description

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 vendors and products

- MongoDB: BI Connector

## Tracked companies

- [MongoDB Atlas](https://rewindex.com/company/mongodb-atlas.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-81517)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-81517)
- [https://www.mongodb.com/docs/bi-connector/current/release-notes/](https://www.mongodb.com/docs/bi-connector/current/release-notes/)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-81517 · Markdown: https://rewindex.com/cve/CVE-2026-81517.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-81517 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:15:34.047Z