Vulnerability · Published Jun 8, 2026 · Assigned by redhat
CVE-2026-3238Samba: denial of service against ad dc wins server
High 7.5
In plain English
A high-severity null pointer dereference in Red Hat Enterprise Linux 10 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 2.7% (higher than 86% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | samba | 4.22.10-r0 | ALPINE-CVE-2026-3238 |
| Alpine:v3.24 | samba | 4.23.8-r0 | ALPINE-CVE-2026-3238 |
| Debian:12 | samba | 2:4.17.12+dfsg-0+deb12u4 | DEBIAN-CVE-2026-3238 |
| Debian:13 | samba | 2:4.22.8+dfsg-0+deb13u2 | DEBIAN-CVE-2026-3238 |
| Debian:14 | samba | 2:4.24.3+dfsg-1 | DEBIAN-CVE-2026-3238 |
| Ubuntu:22.04:LTS | samba | 2:4.15.13+dfsg-0ubuntu1.12 | UBUNTU-CVE-2026-3238 |
| Ubuntu:24.04:LTS | samba | 2:4.19.5+dfsg-4ubuntu9.6 | UBUNTU-CVE-2026-3238 |
| Ubuntu:25.10 | samba | 2:4.22.3+dfsg-4ubuntu2.4 | UBUNTU-CVE-2026-3238 |
| Ubuntu:26.04:LTS | samba | 2:4.23.6+dfsg-1ubuntu2.1 | UBUNTU-CVE-2026-3238 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | see references |
| Red Hat | Red Hat Enterprise Linux 6 | see references |
| Red Hat | Red Hat Enterprise Linux 6 | see references |
| Red Hat | Red Hat Enterprise Linux 7 | see references |
| Red Hat | Red Hat Enterprise Linux 8 | see references |
| Red Hat | Red Hat Enterprise Linux 9 | see references |
| Red Hat | Red Hat OpenShift Container Platform 4 | see references |
Weakness: CWE-476 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://access.redhat.com/security/cve/CVE-2026-3238 vdb-entry, x_refsource_REDHAT
- RHBZ#2486176 issue-tracking, x_refsource_REDHAT
- https://www.samba.org/samba/security/CVE-2026-3238.html
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-3238.json x_sadp-csaf-vex