CVE-2026-50306 is a Windows TCP/IP elevation of privilege vulnerability described as a use-after-free issue. Microsoft rates it High with a CVSS v3.1 base score of 7.8 and temporal score of 6.8. The vector is local-only (AV:L), requires low privileges and no user interaction, and has low attack complexity. If successfully exploited, an attacker could gain SYSTEM privileges, with high confidentiality, integrity, and availability impact. Microsoft lists the exploit status as not publicly disclosed, not exploited, and exploit code maturity as unproven; enterprise risk is primarily for local attack paths rather than network-exposed services.

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 HIGH, integrity HIGH, availability HIGH.
- Exploitation likelihood: Exploitation Less Likely; local attack vector with LOW attack complexity, LOW privileges required, and NO user interaction.
- Severity for enterprise: High technical severity, but real-world enterprise exposure is lower than for network-reachable vulnerabilities because exploitation requires local access and some privileges.
- Patch status: available; customer action required.

Affected systems:
- Windows 10 1607
- Windows 10 1809
- Windows 10 21H2
- Windows 10 22H2
- Windows 11 24H2
- Windows 11 25H2
- Windows 11 26H1
- Windows 11 unspecified
- Windows Server 2012
- Windows Server 2012 R2
- Windows Server 2016
- Windows Server 2019
- Windows Server 2022
- Windows Server 2025