CVE-2026-54128 is a Windows DHCP Client remote code execution vulnerability caused by a use-after-free condition. Microsoft rates it with a CVSS v3.1 base score of 8.4 (High) and a temporal score of 7.3. The vector is local attack only, with low attack complexity, no privileges required, and no user interaction. Microsoft lists exploitation as more likely, but there are no reports of public disclosure or active exploitation and exploit code maturity is unproven. Because the attack vector is local rather than network-based, enterprise risk is lower for internet-facing exposure, but it remains a high-severity issue on affected Windows systems where local execution is possible.

Highlights:
- CVSS scores: Base 8.4 - Temporal 7.3
- Exploit status & code maturity: Publicly Disclosed: No; Exploited: No; Exploit Code Maturity: UNPROVEN
- Impact: Remote Code Execution with HIGH confidentiality, integrity, and availability impacts
- Exploitation likelihood: Exploitation More Likely; vector is LOCAL, with LOW attack complexity, NO privileges required, and NO user interaction
- Severity for enterprise: High severity due to remote code execution and no user interaction, but real-world enterprise exposure is moderated by the local-only attack vector rather than network reachability
- 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