Microsoft Windows DNS: Information disclosure via out-of-bounds read
Summary
A out-of-bounds read in the Windows DNS Server role allows an authorized attacker to read sensitive information over the network. The CVE record rates the impact as confidentiality only, with no integrity or availability impact. The attacker needs high privileges (PR:H) and no user interaction, so an existing privileged foothold, such as an insider or a compromised account, is the realistic scenario.
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
- Windows Server 2025 and Server Core installation: 10.0.26100.0 before 10.0.26100.33822 (unconfirmed, only from aggregators and a sibling CVE)
- Windows 10/11 and older branches: Unknown.
Fixed in
- Install the November 2026 cumulative security update for each affected build.
- Fixed builds: 10.0.14393.9688 (Server 2016), 10.0.17763.9487 (Server 2019), 10.0.20348.5870 (Server 2022), 10.0.26100.33822 (Server 2025, to be confirmed by MSRC).
- KB number: Unknown.
Workaround
- No vendor-confirmed workaround is known.
- Precaution: keep DNS packet debug logging disabled on production servers until MSRC confirms whether it is a precondition.
- Limit which hosts can reach DNS management and query interfaces.
Exploitation
- Exploited in the wild: Not known.
- Public proof of concept: none found. Rapid7 rates exploitation as less likely.
- CISA KEV listing: Unknown.
- CISA SSVC: Exploitation none, not automatable, partial technical impact.
Our recommendation
- Patch all affected Windows Server DNS servers with the November 2026 security update, prioritising internet-facing and multi-role DNS servers, including domain controllers.
- Verify the fixed build numbers on the MSRC page before rollout.
- Restrict administrative access to DNS servers and review privileged accounts.
- Keep DNS debug logging disabled unless needed, and monitor DNS servers for unusual activity.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Information disclosure – Windows DNS
- 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
- CVE Record CVE-2026-96984 www.cve.org
- MSRC Security Update Guide CVE-2026-96984 msrc.microsoft.com
- Rapid7 November 2026 Patch Tuesday analysis www.rapid7.com
- OffSeq threat radar CVE-2026-96984 radar.offseq.com
- Strix CVE-2026-96984 (aggregator) 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, 19:18.
Original description (NVD)
Out-of-bounds read in Windows DNS allows an authorized attacker to disclose information over a network.
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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