CVE-2026-88833

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.

CVSS vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

• https://access.redhat.com/security/cve/CVE-2026-88833
• https://bugzilla.redhat.com/show_bug.cgi?id=2531347