# CVE-2026-106433: Heap corruption via duplicate masterKey fields in MongoDB libmongocrypt

> CVE-2026-106433: Heap corruption via duplicate masterKey fields in MongoDB libmongocrypt. CVSS 8.8 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-106433
Last updated: 2026-10-08T20:49:23Z

- Published: 2026-10-08 18:55 UTC · Updated: 2026-10-08 20:49 UTC · Assigner: mongodb
- CVSS: 8.8 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS: 0.27%, 19th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-843

## Description

Improper state management in MongoDB libmongocrypt can cause provider-specific data to be treated as an incompatible type when cleaning up a key document containing duplicate masterKey fields. An authenticated actor who can modify key vault documents, or a server that returns such a key document, can cause invalid memory access and invalid frees in the client process. This can terminate the application or corrupt process memory.

## Affected vendors and products

- MongoDB: libmongocrypt

## Tracked companies

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

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-106433)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-106433)
- [https://jira.mongodb.org/browse/MONGOCRYPT-964](https://jira.mongodb.org/browse/MONGOCRYPT-964)

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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-2026-106433 · Markdown: https://rewindex.com/cve/CVE-2026-106433.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-106433 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:12:58.065Z