---
id: CVE-2026-106436
title: >-
  The BSON encoder in the MongoDB PHP Driver does not check some return values
  after a document exceeds libbson's size limit
summary: >-
  The BSON encoder in the MongoDB PHP Driver does not check some return values
  after a document exceeds libbson's size limit. This can leave the encoder in
  an invalid state. An unauthenticated actor who can cause an affected
  application to…
severity: medium
cvss: 4.8
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L'
cwe:
  - CWE-252
published: '2026-10-08'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T20:49:23.240'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-106436'
references:
  - url: 'https://jira.mongodb.org/browse/PHPC-2739'
    label: cna@mongodb.com
tags:
  - nvd
ingestedAt: '2026-10-08T21:07:56.432Z'
---

## Overview

The BSON encoder in the MongoDB PHP Driver does not check some return values after a document exceeds libbson's size limit. This can leave the encoder in an invalid state. An unauthenticated actor who can cause an affected application to encode an unusually large data structure can terminate the PHP worker or cause the resulting document to omit fields. No MongoDB server connection or database authentication is required.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.