Microsoft Windows Server DNS Server: Use-after-free elevation of privilege
Summary
A use-after-free flaw (CWE-416) in the DNS Server role of Windows Server allows an authorized local attacker to elevate privileges. The attack requires local access and high privileges on the DNS server, so an attacker must already have administrator-level access before exploiting it. The vendor rates the issue as Important; CVSS 6.7 (Medium).
Affected
- Windows Server 2016 and Server Core installation: 10.0.14393.0 before 10.0.14393.9688
- Windows Server 2019 and Server Core installation: 10.0.17763.0 before 10.0.17763.9487
- Windows Server 2022: 10.0.20348.0 before 10.0.20348.5870 (per CVE record)
- Windows Server 2025 and Server Core installation: 10.0.26100.0 before 10.0.26100.33822 (per CVE record)
Fixed in
- Update to the November 2026 security update for the affected Windows Server version.
- Verify the fixed builds on the MSRC advisory before rollout; the 2022 and 2025 values were not confirmed from the vendor page.
Workaround
Unknown. No vendor-published workaround is known.
- Interim hardening (not vendor-specific): restrict local logon and administrator rights on DNS servers, limit membership in privileged groups such as local Administrators and DnsAdmins, and remove the DNS role from hosts that do not need it.
Exploitation
- Exploited in the wild: not known.
- Rapid7 rates exploitation as less likely; not publicly disclosed.
- Public proof of concept: none found.
Our recommendation
- Patch DNS servers with the November 2026 update, starting with domain controllers and DNS servers with domain admin exposure.
- Check whether the DNS Server role is installed and remove it where it is not needed.
- Restrict local admin and DnsAdmins membership on DNS hosts.
- Monitor privilege changes and administrative logons on DNS servers.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Role: DNS Server
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5131291, KB5131085, KB5131090, KB5131080, KB5131077
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-96179 msrc.microsoft.com
- CVE Record CVE-2026-96179 www.cve.org
- Rapid7: November 2026 Patch Tuesday www.rapid7.com
- BleepingComputer: November 2026 Patch Tuesday www.bleepingcomputer.com
- OffSeq Threat Radar: CVE-2026-96179 radar.offseq.com
- Strix AI: CVE-2026-96179 www.strix.ai
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 11:28.
Original description (NVD)
Use after free in DNS Server allows an authorized attacker to elevate privileges locally.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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