---
id: CVE-2026-88830
title: >-
  A unit confusion in BusyBox TLS Montgomery reduction buffer allocation causes
  a pre-authentication heap buffer overflow when processing a crafted
  ClientKeyExchange message.
summary: >-
  A unit confusion in BusyBox TLS Montgomery reduction buffer allocation causes
  a pre-authentication heap buffer overflow when processing a crafted
  ClientKeyExchange message.
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-131
vendor: Red Hat
product: busybox
affected:
  - busybox (all versions)
published: '2026-09-23'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T20:17:20.750'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-88830'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-88830'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2531344'
    label: secalert@redhat.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-88830.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-88830'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-88830'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-23T18:36:12.931893Z'
ingestedAt: '2026-09-23T17:28:14.849Z'
epss: 0.00351
epssPercentile: 0.26054
---

## Overview

A unit confusion in BusyBox TLS Montgomery reduction buffer allocation causes a pre-authentication heap buffer overflow when processing a crafted ClientKeyExchange message.

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Hardened Images · no fix planned: Red Hat Hardened Images · updated 2026-09-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-88830.json)