Microsoft Windows Server DNS: Out-of-bounds read leads to information disclosure
Summary
An out-of-bounds read in the DNS server component of Windows Server allows an authorized attacker to read memory contents beyond the allocated buffer over the network. The CVSS base score is 4.9 (medium), with impact limited to confidentiality. Exploitation requires high privileges, and no exploitation has been observed so far.
Affected
- Windows Server 2016 and 2016 (Server Core): 10.0.14393.0 before 10.0.14393.9688
- Windows Server 2019 and 2019 (Server Core): 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 2025 (Server Core): 10.0.26100.0 before 10.0.26100.33822 (third-party source, to be verified against MSRC)
Fixed in
- Windows Server 2016 and 2016 (Server Core): 10.0.14393.9688 or later
- Windows Server 2019 and 2019 (Server Core): 10.0.17763.9487 or later
- Windows Server 2022: 10.0.20348.5870 or later
- Windows Server 2025 and 2025 (Server Core): 10.0.26100.33822 or later (third-party source, to be verified against MSRC)
- Included in the November 2026 Patch Tuesday updates. KB numbers: Unknown.
Workaround
Unknown. No vendor-documented workaround was found. Apply the security updates.
Exploitation
- Not known to be exploited.
- No public proof of concept found.
- Rapid7 rates exploitation as less likely.
- CISA SSVC: Exploitation none, automatable no, technical impact partial.
Our recommendation
- Identify all Windows Server systems running the DNS role, especially those reachable from the internet or less-trusted internal segments.
- Install the November 2026 cumulative updates on these systems, prioritizing exposed DNS servers.
- Restrict high-privilege accounts and check for unusual administrative logons.
- Monitor for unexpected behavior on DNS servers.
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
- Microsoft Security Update Guide: CVE-2026-96987 msrc.microsoft.com
- CVE Record CVE-2026-96987 www.cve.org
- VulDB: CVE-2026-96987 vuldb.com
- OffSeq Radar: CVE-2026-96987 radar.offseq.com
- Rapid7: November 2026 Patch Tuesday www.rapid7.com
- Cybersecurity News: Microsoft November 2026 Patch Tuesday cybersecuritynews.com
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, 19:34.
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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