# CVE-2026-81522: Cross-tenant database retargeting via dot/NUL injection in namespace strings in the C++ Driver

> CVE-2026-81522: Cross-tenant database retargeting via dot/NUL injection in namespace strings in the C++ Driver. CVSS 8.1 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-81522
Last updated: 2026-09-29T19:17:22Z

- Published: 2026-08-27 18:32 UTC · Updated: 2026-09-29 19:17 UTC · Assigner: mongodb
- CVSS: 8.1 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- EPSS: 0.46%, 40th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-116

## Description

A weakness in the MongoDB C++ Driver's handling of caller-supplied namespace identifiers allows special characters embedded in those identifiers. An application that builds a namespace identifier from untrusted input without validating it may therefore have its operation directed at a different target than intended. This can result in limited unauthorized read and write access to data belonging to another logical tenant of the affected application.

## Affected vendors and products

- MongoDB: C++ Driver

## Tracked companies

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

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-81522)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-81522)
- [https://github.com/mongodb/mongo-cxx-driver/releases/tag/r4.5.1](https://github.com/mongodb/mongo-cxx-driver/releases/tag/r4.5.1)
- [https://jira.mongodb.org/browse/CXX-3552](https://jira.mongodb.org/browse/CXX-3552)

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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-2026-81522 · Markdown: https://rewindex.com/cve/CVE-2026-81522.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-81522 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:13:35.227Z