CVE-2026-3238 PUBLISHED

Samba: denial of service against ad dc wins server

Assigner: redhat
Reserved: 26.02.2026 Published: 08.06.2026 Updated: 08.06.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 7.5

Product Status

Vendor Red Hat
Product Red Hat Enterprise Linux 10
Versions Default: unknown
Vendor Red Hat
Product Red Hat Enterprise Linux 6
Versions Default: unknown
Vendor Red Hat
Product Red Hat Enterprise Linux 6
Versions Default: unknown
Vendor Red Hat
Product Red Hat Enterprise Linux 7
Versions Default: unknown
Vendor Red Hat
Product Red Hat Enterprise Linux 8
Versions Default: unknown
Vendor Red Hat
Product Red Hat Enterprise Linux 9
Versions Default: unknown
Vendor Red Hat
Product Red Hat OpenShift Container Platform 4
Versions Default: unknown

Workarounds

As a workaround, deployments that do not strictly require Samba-provided WINS functionality should disable WINS support by removing: wins support = yes from the Samba configuration.

Credits

  • Red Hat would like to thank Arad Inbar (DREAM Security Research Team), Ben Grinberg (DREAM Security Research Team), Erez Cohen (DREAM Security Research Team), and Nir Somech (DREAM Security Research Team) for reporting this issue.

References

Problem Types

  • NULL Pointer Dereference CWE