---
title: "CVE-2026-106433: MongoDB libmongocrypt - Out of Bounds Read/Write"
description: "MongoDB libmongocrypt contains an out-of-bounds memory access caused by improper state management when cleaning up key documents with duplicate masterKey fields, letting authenticated actors cause application termination or memory corruption, exploit requires ability to modify key vault documents."
url: https://panop.io/threat-heartbeat/CVE-2026-106433/
---

# CVE-2026-106433 MongoDB libmongocrypt - Out of Bounds Read/Write

MongoDB libmongocrypt contains an out-of-bounds memory access caused by improper state management when cleaning up key documents with duplicate masterKey fields, letting authenticated actors cause application termination or memory corruption, exploit requires ability to modify key vault documents.

CVSS base score 8.8 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.27% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-106433)

## Details

Type

Out of Bounds Read/Write

Impact

Denial Of Service

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Published

8 October 2026

Updated

15 October 2026

Weakness

[CWE-843](https://cwe.mitre.org/data/definitions/843.html)

## Vendor fix

Update to the latest version of libmongocrypt containing the fix.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-106433](https://nvd.nist.gov/vuln/detail/CVE-2026-106433)
- [https://jira.mongodb.org/browse/MONGOCRYPT-964](https://jira.mongodb.org/browse/MONGOCRYPT-964)

[← All CVEs](https://panop.io/threat-heartbeat/)

## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

[Book a demo](https://panop.io/demo)