Use-after-free in Microsoft Windows and Windows Server - CVE-2026-96983

Vulnerability identifier: #VU165788

CSH Severity: Medium

CVSS v4: 6 [CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-96983

CWE-ID: CWE-416

Exploitation vector: Adjecent network

Exploit availability: No public exploit available

The vulnerability allows a remote attacker on the local network to cause a denial of service in Windows DNS.

The vulnerability exists due to use-after-free in Windows DNS when handling network traffic. A remote attacker on the local network can send specially crafted traffic over an adjacent network to trigger access to freed memory and cause a denial of service.

Microsoft Windows
Windows Server

Install security update from vendor's website.

Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7846, 10 22H2 10.0.19045.7846, 10 1607 10.0.14393.9688, 10 1809 10.0.17763.9487, 11 23H2 10.0.22631.7711, 11 24H2 10.0.26100.9911, 11 24H2 10.0.26100.9974, 11 25H2 10.0.26200.9911, 11 25H2 10.0.26200.9974, 11 26H1 10.0.28000.3501
Windows Server - addressed in versions 2016 10.0.14393.9688, 2019 10.0.17763.9487, 2022 10.0.20348.5870, 2025 10.0.26100.33730, 2025 10.0.26100.33822

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-96983
• https://support.microsoft.com/help/5131291

• Multiple vulnerabilities in Microsoft Windows