Medium · CVSS 6.5CVE-2026-88833

Busybox: busybox: udhcpc integer underflow in dhcp packet length calculation causes denial of serviceCVE-2026-88833

Answer in brief

CVE-2026-88833 records a Medium severity (CVSS 6.5) vulnerability in Busybox: busybox: udhcpc integer underflow in dhcp packet length calculation causes denial of service. The current sources do not mark it as known exploited. The current feed maps Red Hat/busybox (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 13, 2026Updated Oct 13, 2026Source checked Oct 13, 2026First seen by HOL Oct 13, 2026Material review Oct 13, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.5
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 6.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Red Hat/busybox (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Red Hat/busyboxgeneric	*	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Red Hat/busybox.
Review the reported fix. Source-reported workaround: If feasible, use udhcpc in LISTEN_KERNEL mode instead of LISTEN_RAW, or use an alternative DHCP client (dhclient, systemd-networkd). Restrict DHCP traffic on the local segment (for example DHCP snooping on switches).

Evidence timeline and material changes

Published upstream
Oct 13, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 13, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 13, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.