CVE-2026-49800 is a Windows Web Proxy Auto-Discovery Protocol (WPAD) elevation of privilege vulnerability caused by an integer overflow or wraparound. It has a CVSS v3.1 base score of 7.8 (High) and a temporal score of 6.8. The vector is local-only with low attack complexity, low privileges required, no user interaction, and unchanged scope. Microsoft reports no public disclosure and no known exploitation, with exploit code maturity listed as UNPROVEN. Because this is a local elevation of privilege issue, enterprise risk is mainly for systems where attackers already have local access or can run code on the target.

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 with HIGH confidentiality, HIGH integrity, and HIGH availability impact.
- Exploitation likelihood: Exploitation Less Likely; local attack vector, LOW attack complexity, LOW privileges required, and NO user interaction.
- Severity for enterprise: High severity by CVSS, but lower enterprise exposure than network-based issues because exploitation requires local access. Risk is more relevant on endpoints or servers where untrusted local users, code execution, or shared access exists.
- Patch status: available; customer action required.

Affected systems:
- Windows 10 1809
- Windows 10 21H2
- Windows 10 22H2
- Windows 11 24H2
- Windows 11 25H2
- Windows 11 26H1
- Windows 11 unspecified
- Windows Server 2019
- Windows Server 2022
- Windows Server 2025