# CVE-2026-3238: Samba: denial of service against ad dc wins server

> An unauthenticated remote attacker can crash the Samba WINS service on Active Directory Domain Controllers via crafted UDP packets.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/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:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 Jun 2026
- **Updated:** 1 Sep 2026
- **Also known as:** ALPINE-CVE-2026-3238, AZL-89519, CLSA-2026-1782159797, DEBIAN-CVE-2026-3238, ECHO-4f6e-0017-81fd, GHSA-gpff-px68-36rh, UBUNTU-CVE-2026-3238

## What is CVE-2026-3238?

CVE-2026-3238 is a high-severity vulnerability in Red Hat Enterprise Linux 10, published on 8 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw was found in Samba’s WINS server component when running as an Active Directory Domain Controller. The WINS protocol handlers for certain request types did not properly validate incoming packets, allowing an unauthenticated remote attacker to trigger a NULL pointer dereference and crash the WINS service using specially crafted UDP packets.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-3238?


## How do I fix CVE-2026-3238?

Apply the vendor's patch.

## Is CVE-2026-3238 being exploited?

There is no known exploitation of CVE-2026-3238 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-3238 and fix it if it is affected.

What it is: CVE-2026-3238 is a high-severity vulnerability in Red Hat Enterprise Linux 10, published on 8 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-3238 in the wild and no public exploit code.

Affected product: Red Hat Enterprise Linux 10. 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-2026-3238/ (Markdown: https://insights.sbomify.com/CVE-2026-3238/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3238
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3238
- OSV: https://osv.dev/vulnerability/CVE-2026-3238

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-3238/
Summaries are generated and may contain mistakes; the official description above is the record.