# CVE-2026-106437: Out-of-bounds read and write via undersized BSON buffer reservation in MongoDB C Driver

> CVE-2026-106437: Out-of-bounds read and write via undersized BSON buffer reservation in MongoDB C Driver. CVSS 6.2 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-106437
Last updated: 2026-10-08T20:49:23Z

- Published: 2026-10-08 18:42 UTC · Updated: 2026-10-08 20:49 UTC · Assigner: mongodb
- CVSS: 6.2 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H
- EPSS: 0.10%, 1th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-191

## Description

The BSON buffer-reservation API in the MongoDB C Driver can record a length smaller than the five-byte BSON minimum. Later append or comparison operations can underflow unsigned length calculations and read or write outside the document buffer. An actor who can influence the length supplied by an embedding application can cause the application to terminate or read or corrupt adjacent process memory. Reaching this issue requires the application to pass an undersized value to bson\_reserve\_buffer and then perform an affected operation.

## 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-2026-106437)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-106437)
- [https://jira.mongodb.org/browse/CDRIVER-6423](https://jira.mongodb.org/browse/CDRIVER-6423)

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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-2026-106437 · Markdown: https://rewindex.com/cve/CVE-2026-106437.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-106437 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:13:36.873Z