CVE-2026-97842 Microsoft CVE debrief

Who should care

Defenders responsible for Windows and Windows Server systems, especially those managing DNS servers or networks with internet exposure, should assess their systems for vulnerability and apply patches promptly.

Why it matters

CVE-2026-97842 is a MEDIUM-severity vulnerability in DNS Server that allows authorized attackers to disclose information. Defenders should prioritize patching and monitoring affected systems.

• Potential information disclosure over the network
• Need to verify and apply patches to affected systems
• Monitoring DNS server logs for suspicious activity is recommended
• Restricting access to DNS server configuration may be necessary

Technical summary

The vulnerability is caused by an out-of-bounds read in the DNS Server, allowing authorized attackers to disclose information over a network. Affected systems include Windows 10 Version 1607, Windows 10 Version 1809, Windows 10 Version 21H2, Windows 10 Version 22H2, Windows 11 version 23H2, Windows 11 Version 23H2, Windows 11 Version 24H2, Windows 11 Version 25H2, Windows 11 version 26H1, Windows 11 Version 26H2, Windows Server 2012, Windows Server 2012 (Server Core installation), Windows Server 2012 R2, Windows Server 2012 R2 (Server Core installation), Windows Server 2016, Windows Server 2016 (Server Core installation), Windows Server 2019, Windows Server 2019 (Server Core installation), Windows Server 2022, and Windows Server 2025.

Defensive priority

Defenders should prioritize patching affected systems, especially those exposed to the internet or untrusted networks, to prevent potential information disclosure.

Recommended defensive actions

• Patch affected Windows 10, Windows 11, and Windows Server versions
• Verify and apply Microsoft's security updates
• Monitor DNS server logs for suspicious activity
• Restrict access to DNS server configuration

Evidence notes

The CVE Program and NVD provide official records of the vulnerability. Microsoft has released a patch for the affected systems. The vulnerability affects multiple Windows versions and server editions, including Windows 10, Windows 11, and Windows Server from 2012 to 2025. Defenders should verify and apply patches to affected systems, review DNS server logs for suspicious activity, and restrict access to DNS server configuration if necessary. The information provided is based on the CVE

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.