---
id: CVE-2026-88833
title: A flaw was found in BusyBox's udhcpc DHCP client
summary: >-
  A flaw was found in BusyBox's udhcpc DHCP client. When processing raw DHCP
  packets, the client replaces the validated packet length with an
  attacker-controlled value from the IP header without re-validating the minimum
  size. This leads t…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-191
published: '2026-10-13'
updated: '2026-10-13'
sourceUpdated: '2026-10-13T17:17:48.007'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-88833'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-88833'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2531347'
    label: secalert@redhat.com
tags:
  - nvd
ingestedAt: '2026-10-13T17:38:53.200Z'
---

## Overview

A flaw was found in BusyBox's udhcpc DHCP client. When processing raw DHCP packets, the client replaces the validated packet length with an attacker-controlled value from the IP header without re-validating the minimum size. This leads to an integer underflow when subtracting header sizes, causing a subsequent memory copy with a massively oversized length. An attacker on the same network segment can send a specially crafted packet to crash the DHCP client, resulting in denial of service and loss of network connectivity.

## Remediation

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