CVE-2026-49175 is a Windows DNS Client heap-based buffer overflow that can be used for elevation of privilege to SYSTEM. Microsoft rates it as High severity with a CVSS v3.1 base score of 7.8 and temporal score of 6.8. The attack vector is local, with low attack complexity, low privileges required, and no user interaction. Microsoft reports no public disclosure and no known exploitation, with exploit code maturity unproven. Because this is a local-only privilege escalation issue, enterprise risk is highest on systems where untrusted local code or users can run.

Highlights:
- CVSS scores: Base 7.8 - Temporal 6.8
- Exploit status & code maturity: Publicly Disclosed: No; Exploited: No; Exploit Code Maturity: UNPROVEN.
- Impact: Elevation of Privilege; confidentiality, integrity, and availability impacts are all HIGH if successfully exploited. FAQ states an attacker could gain SYSTEM privileges.
- Exploitation likelihood: Exploitation Less Likely; vector context is LOCAL with LOW attack complexity, LOW privileges required, and NO user interaction.
- Severity for enterprise: High technical severity, but lower exposure than network-reachable issues because exploitation requires local access. Risk is more relevant on shared or multi-user Windows systems and endpoints where untrusted local code may run.
- Patch status: available; customer action required.

Affected systems:
- Windows 10 21H2
- Windows 10 22H2
- Windows 11 24H2
- Windows 11 25H2
- Windows 11 26H1
- Windows 11 unspecified
- Windows Server 2022
- Windows Server 2025