---
id: CVE-2026-88840
title: >-
  BusyBox TLS get_client_hello() reads past the end of the input buffer when
  parsing a truncated ClientHello message.
summary: >-
  BusyBox TLS get_client_hello() reads past the end of the input buffer when
  parsing a truncated ClientHello message.
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-125
vendor: Red Hat
product: busybox
affected:
  - busybox (all versions)
published: '2026-09-23'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T19:40:10.000'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-88840'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-88840'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2531354'
    label: secalert@redhat.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-88840.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-88840'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-88840'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ingestedAt: '2026-09-23T18:29:33.147Z'
epss: 0.00205
epssPercentile: 0.09268
---

## Overview

BusyBox TLS get_client_hello() reads past the end of the input buffer when parsing a truncated ClientHello message.

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Moderate · updated 2026-09-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-88840.json)