# 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.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Oct 2026
- **Updated:** 16 Oct 2026
- **Also known as:** AZL-108321, BELL-CVE-2026-88833, DEBIAN-CVE-2026-88833, GHSA-hg7w-cw6w-99w3, UBUNTU-CVE-2026-88833

## 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 (Integer Underflow (Wrap or Wraparound))

## 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.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-88833 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-88833 in the wild and no public exploit code.

Affected product: Red Hat Hardened Images. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-88833/ (Markdown: https://insights.sbomify.com/CVE-2026-88833/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-88833
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-88833
- OSV: https://osv.dev/vulnerability/CVE-2026-88833

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-88833/
Summaries are generated and may contain mistakes; the official description above is the record.