Microsoft Closes Critical Security Gaps on Patch Tuesday

Important update

Patchday: Attackers exploit Windows vulnerabilities

Microsoft has closed 58 security holes. Attackers are already exploiting six of them. Users should act urgently.

Microsoft closed a total of 58 security vulnerabilities in Windows, Office and other products as part of its February Patch Day (on the second Tuesday of the month). Six of these vulnerabilities have already been actively exploited by attackers, the company says in its Security Update Guide. The US cybersecurity agency CISA has included all six vulnerabilities in its catalog of known exploited vulnerabilities.

The vulnerabilities attacked are holes in Windows Shell, Word, the Desktop Window Manager, Remote Desktop, Internet Explorer and Windows Remote Access. In most cases, users have to open manipulated links or launch crafted documents for the attacks to work.

A vulnerability in Windows Shell (CVE-2026-21510) allows attackers to bypass the SmartScreen protection mechanism. This usually warns against opening potentially dangerous applications. If attacks are successful, programs contaminated with malicious code could start without warning.

Another exploited vulnerability affects Microsoft Word (CVE-2026-21514). Here, victims have to open a manipulated document, whereupon malicious code is executed. The vulnerabilities in Desktop Window Manager (CVE-2026-21519) and Windows Remote Desktop (CVE-2026-21533) give attackers higher user privileges.

The vulnerabilities in Internet Explorer (CVE-2026-21513) and Windows Remote Access (CVE-2026-21525) lead to crashes or also allow privilege escalation.

In addition to the vulnerabilities that have already been exploited, Microsoft has also closed gaps in its Azure cloud platform, the AI-supported programming assistant GitHub Copilot, in Defender and in the Windows NTLM authentication protocol. Malicious code can enter systems through these vulnerabilities or information can leak.

Microsoft provides different update packages for the different Windows 11 versions. Version 26H1 receives the update KB5077179, while versions 24H2 and 25H2 receive KB5077181. Users of version 23H2 get KB5075941. The cumulative update KB5075912 is available for Windows 10.

Users should ensure that Windows Update is active and the latest security patches are installed to protect their systems from actively exploited vulnerabilities.