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

7.5HIGH

Key Information:

Vendor

Red Hat
Status
Red Hat Enterprise Linux 10
Red Hat Enterprise Linux 6
Red Hat Enterprise Linux 7
Red Hat Enterprise Linux 8
Vendor
CVE Published:
8 June 2026

What is CVE-2026-3238?

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.

References

https://access.redhat.com/security/cve/CVE-2026-3238
vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2486176
issue-trackingx_refsource_REDHAT
https://www.samba.org/samba/security/CVE-2026-3238.html

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

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.
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