---
id: GHSA-86gh-39m5-hhg6
title: >-
  Duplicate Advisory: PYTHON-6110 Out-of-bounds read in BSON decoding via a
  malformed Regex element
summary: >-
  Duplicate Advisory: PYTHON-6110 Out-of-bounds read in BSON decoding via a
  malformed Regex element
severity: medium
cvss: 5.1
cwe:
  - CWE-125
vendor: pymongo
product: pymongo
ecosystem: pip
affected:
  - 'pymongo >= 3.9.0, <= 4.18.2'
published: '2026-10-08'
updated: '2026-10-27'
sourceUpdated: '2026-10-27T15:36:26Z'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-86gh-39m5-hhg6'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-106435'
  - url: 'https://jira.mongodb.org/browse/PYTHON-6110'
  - url: 'https://github.com/advisories/GHSA-86gh-39m5-hhg6'
tags:
  - ghsa
  - pip
ingestedAt: '2026-10-27T16:11:58.708Z'
---

## Overview

## Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-98qm-wvgf-w4cf. This link is maintained to preserve external references.

## Original Description
The MongoDB Python Driver's binary accelerator can read outside a buffer when an application decodes malformed BSON containing a truncated regular-expression element without a trailing NUL byte. An actor who can supply BSON to the documented decode or decode_all API can cause the application process to terminate when the C extension is loaded. The driver's normal database wire-protocol path does not reach this code.

## Affected packages

- `pymongo >= 3.9.0, <= 4.18.2`

## Remediation

Refer to the advisory for the patched release.