# CVE-2026-81518: BI Connector Optional Client Certificate Verification Allows Unauthenticated Connections

> CVE-2026-81518: BI Connector Optional Client Certificate Verification Allows Unauthenticated Connections. CVSS 7.5 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-81518
Last updated: 2026-09-29T19:14:48Z

- Published: 2026-08-28 20:18 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:H/I:N/A:N
- EPSS: 0.25%, 17th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-295

## Description

When mongosqld is configured with a client certificate authority file, the listener requests a client certificate during the TLS handshake but does not require one, so a client that presents no certificate is still accepted. In deployments that rely on client certificates as the sole means of identifying users, a remote party with network access to the listener can therefore establish a session and read the MongoDB data exposed through the connector.

## 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-2026-81518)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-81518)
- [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-2026-81518 · Markdown: https://rewindex.com/cve/CVE-2026-81518.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-81518 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:12:31.931Z