cve 2026 20929

CVE-2026-20929 is a Microsoft-identified elevation of privilege vulnerability in the Windows HTTP Protocol Stack (HTTP.sys). HTTP.sys is a kernel-mode component that handles HTTP requests for IIS and other Windows services. Because it runs in kernel mode, a successful exploit could allow an attacker to gain elevated privileges on an affected system. Microsoft has published a security advisory and recommends that administrators prioritize patching, especially for internet-facing Windows hosts. The vulnerability is listed in the Microsoft Security Update Guide with limited technical details, but the vendor's exploitability signals indicate it should be treated as a high priority for remediation.