Windows DNS Server: Information disclosure through out-of-bounds read
Summary
Windows DNS Server on Windows Server 2016, 2019, 2022 and 2025 contains an out-of-bounds read that allows information disclosure over the network. Microsoft describes that an attacker can read heap memory from a privileged process on the server. The attacker needs high privileges, so the risk is limited. The CVSS base score is 4.9 (Medium), with impact on confidentiality only.
Affected
- Windows Server 2016 and Server Core installation: before 10.0.14393.9688
- Windows Server 2019 and Server Core installation: before 10.0.17763.9487
- Windows Server 2022: before 10.0.20348.5870
- Windows Server 2025 and Server Core installation: before 10.0.26100.33822
Fixed in
- Windows Server 2016: 10.0.14393.9688 or later
- Windows Server 2019: 10.0.17763.9487 or later
- Windows Server 2022: 10.0.20348.5870 or later (not confirmed on the MSRC page)
- Windows Server 2025: 10.0.26100.33822 or later
- KB numbers: confirm on the MSRC page before rollout
Workaround
Unknown. No vendor-documented workaround was found. Patching is the fix.
Exploitation
- No evidence of exploitation in the wild.
- No public proof of concept known.
- Microsoft rates exploitation as less likely and public disclosure as no.
- Not listed in CISA KEV (per a third-party summary; CISA KEV not checked directly).
Our recommendation
- Identify Windows Server systems with the DNS role on affected versions.
- Install the November 2026 cumulative updates on DNS servers with normal priority, after confirming the exact fixed build on the MSRC page.
- Restrict DNS management interfaces to administrative networks.
- Check that DNS services are not exposed to the internet.
- 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
- Microsoft Security Update Guide: CVE-2026-119971 msrc.microsoft.com
- CVE Record: CVE-2026-119971 www.cve.org
- Senserva: KB5131085 summary senserva.com
- Strix.ai: CVE-2026-119971 (cross-check) www.strix.ai
- Rapid7: Patch Tuesday November 2026 www.rapid7.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, 19:37.
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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