CVE-2026-3238: Samba: denial of service against ad dc wins server
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.
Other sources
The WINS server component of the Active Directory Domain controller code in Samba is vulnerable to a NULL pointer dereference and crash caused by a unauthenticated UDP packet.
— Red Hat
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/sambato a version that resolves this vulnerability.Fixed in 2:4.17.12+dfsg-0+deb12u4Fixed in 2:4.22.11+dfsg-0+deb13u1Fixed in 2:4.22.10+dfsg-0+deb13u2Fixed in 2:4.25.1+dfsg-1
Event History
Frequently Asked Questions
What is the severity of CVE-2026-3238?
The severity of CVE-2026-3238 is classified as high with a score of 7.5.
How does CVE-2026-3238 affect Samba servers?
CVE-2026-3238 affects Samba servers by allowing an unauthenticated remote attacker to crash the WINS server through a denial of service attack.
What is the main cause of CVE-2026-3238?
CVE-2026-3238 is caused by improper validation of incoming packets in the WINS protocol handlers.
How can I mitigate CVE-2026-3238?
Mitigation for CVE-2026-3238 involves applying the latest security updates and patches provided by the Samba project.
Can CVE-2026-3238 be exploited remotely?
Yes, CVE-2026-3238 can be exploited remotely by unauthenticated attackers.