CVE-2026-88833 Busybox: busybox: udhcpc integer underflow in dhcp packet length calculation causes denial of service
An attacker on the same network can crash the BusyBox udhcpc client via a crafted DHCP packet, causing denial of service and loss of connectivity.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-88833?
CVE-2026-88833 is a medium-severity vulnerability in Red Hat Hardened Images, published on 13 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-191
Which versions are affected by CVE-2026-88833?
How do I fix CVE-2026-88833?
Apply the vendor's patch.
Is CVE-2026-88833 being exploited?
There is no known exploitation of CVE-2026-88833 in the wild and no public exploit code.
Sources
Also known as AZL-108321, BELL-CVE-2026-88833, DEBIAN-CVE-2026-88833, GHSA-hg7w-cw6w-99w3, UBUNTU-CVE-2026-88833.