Windows DNS: Out-of-bounds read causing information disclosure
Summary
Microsoft Windows Server DNS Server role contains an out-of-bounds read (CWE-125). An authorized attacker with high privileges can read memory over the network and disclose information. No impact on integrity or availability is described, and the flaw is not reachable without prior authentication.
Affected
- Windows Server 2016 (including Server Core): builds before 10.0.14393.9688
- Windows Server 2019 (including Server Core): builds before 10.0.17763.9487
- Windows Server 2022: builds before 10.0.20348.5870 (from third-party sources, not yet confirmed by MSRC)
- Windows Server 2025 (including Server Core): builds before 10.0.26100.33822 (from third-party sources, not yet confirmed by MSRC)
Fixed in
- Install the November 2026 cumulative update for each affected build. The fixed builds are listed above; check the MSRC advisory for the exact KB numbers.
- Unknown for the exact KB numbers, as the MSRC advisory could not be retrieved.
Workaround
- Unknown. Microsoft documents no workaround.
- General hardening: restrict DNS server access to trusted subnets.
Exploitation
- No known exploitation in the wild.
- Not publicly disclosed, and no public proof-of-concept code found.
- CISA SSVC: exploitation none, not automatable, partial technical impact.
Our recommendation
- Patch the DNS Server role on Windows Server, starting with domain controllers, even though the rating is low.
- Check the Microsoft lifecycle status of Server 2016 and 2019, as patches may end soon.
- Limit who holds administrative privileges, since the attack requires high privileges.
- Restrict DNS access to trusted networks and monitor for unusual DNS server 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 (MSRC) msrc.microsoft.com
- CVE Record CVE-2026-96976 www.cve.org
- Rapid7 November 2026 Patch Tuesday www.rapid7.com
- OffSeq threat radar radar.offseq.com
- Strix CVE summary www.strix.ai
- VulDB CVE-2026-96976 vuldb.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, 19:35.
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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