Microsoft Patches Exploited Windows Zero-Day, 111 Other Vulnerabilities

Microsoft’s January 2026 Patch Tuesday fixes address 112 vulnerabilities, including a zero-day that has been actively exploited in attacks, tracked as CVE-2026-20805 in the Desktop Windows Manager component of Windows. According to SecurityWeek, the vulnerability allows an authorised attacker to disclose information locally, exposing a section address from a remote ALPC port in memory.

Trend Micro’s ZDI notes that threat actors have likely exploited the flaw in targeted attacks as part of an exploit chain to achieve arbitrary code execution. Two other Windows vulnerabilities disclosed before the fixes were: CVE-2026-21265 (Secure Boot bypass) and CVE-2023-31096 (privilege escalation), with Microsoft assessing the latter as more likely to be exploited in the wild.

Eight Windows and Office vulnerabilities patched this month have a critical severity rating, with many exploitable for remote code execution or privilege escalation, and the updates also address flaws in Azure and SharePoint. Written by Eduard Kovacs, the piece is dated 13 January 2026. according to SecurityWeek.