Windows DNS Server: Out-of-bounds read leads to information disclosure
Summary
A flaw in the DNS Server role of Windows allows an out-of-bounds read. An authorized attacker with a low-privilege account on the network can disclose information. Only confidentiality is affected, and no code execution is described.
Affected
- Windows 10 Version 1607 and Windows Server 2016 (build 10.0.14393.0 before 10.0.14393.9612)
- Windows 10 Version 1809 (build 10.0.17763.0 before 10.0.17763.9376)
- Windows 10 Version 21H2 (before 10.0.19044.7807) and 22H2 (before 10.0.19045.7807)
- Windows 11 Version 23H2 (before 10.0.22631.7652), 24H2 and 25H2 (before 10.0.26100.9711 and 10.0.26200.9711), 26H1 (before 10.0.28000.3231), 26H2 (before 10.0.26300.9711)
- Windows Server 2012 and 2012 R2 (before 6.2.9200.26434 and 6.3.9600.23470, per CNA record; verify on MSRC)
Fixed in
- Windows 10 1607 and Windows Server 2016: build 10.0.14393.9612 (KB number unknown)
- Windows 10 1809: build 10.0.17763.9376 (KB5126651 per aggregator)
- Other versions: install the current update listed in the MSRC Security Update Guide
Workaround
Unknown. Microsoft has published no workaround.
Interim measure (not from a vendor source): restrict who can query or manage the DNS server, and limit zone transfers and management access to trusted hosts.
Exploitation
- No evidence of exploitation in the wild found; not listed in CISA KEV in our research (re-check)
- CISA SSVC: exploitation none, automatable no, technical impact partial
- Microsoft temporal rating: E:U (unproven exploit)
- EPSS 0.00953 (low)
- No public proof of concept found
Our recommendation
- Patch Windows DNS servers in the normal cycle, starting with Windows Server 2016 and any internet-facing or sensitive internal DNS servers.
- Verify the Microsoft support status of Windows 10 1607 before planning the update, and replace unsupported systems.
- Restrict DNS query and management access to trusted hosts.
- Check MSRC for the KB number of build 14393.9612 and monitor for exploitation reports.
Information from Microsoft (Patch Tuesday October 2026)
- Severity (Microsoft)
- Important
- Impact
- Information disclosure – 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)
- KB5126835, KB5126836, KB5126868, KB5126651, KB5126657, KB5126655
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-108128 msrc.microsoft.com
- NVD mirror on Vulners vulners.com
- CNA record on Vulners vulners.com
- Tenable CVE page (EPSS) www.tenable.com
- Strix CVE page 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 5 Nov 2026, 11:31.
Original description (NVD)
Out-of-bounds read in DNS Server 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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