Microsoft Windows: 3 exploited vulnerabilities (CVE-2011-3402, CVE-2013-3918, CVE-2021-43226)

CVE-2011-3402: Microsoft Windows Kernel contains an unspecified vulnerability in the TrueType font parsing engine in win32k.sys in the kernel-mode drivers that allows remote attackers to execute arbitrary code via crafted font data in a Word document or web page. CVE-2013-3918: Microsoft Windows contains an out-of-bounds write vulnerability in the InformationCardSigninHelper Class ActiveX control, icardie.dll. An attacker could exploit the vulnerability by constructing a specially crafted webpage. When a user views the webpage, the vulnerability could allow remote code execution. An attacker who successfully exploited this vulnerability could gain the same user rights as the current user. The impacted product could be end-of-life (EoL) and/or end-of-service (EoS). Users should discontinue product utilization. CVE-2021-43226: Microsoft Windows Common Log File System Driver contains a privilege escalation vulnerability that could allow a local, privileged attacker to bypass certain security mechanisms. Added to CISA KEV on 2025-10-06.

Why this severity: CVSS 8.8 (CISA ADP, v3.1); actively exploited (CISA KEV); known ransomware use

Started

Oct 6, 2025

Closed

Oct 6, 2025

CVEs

CVE-2011-3402CVE-2013-3918CVE-2021-43226

• Microsoft
• Windows
• Ransomware
• CISA KEV
• RCE

Notes & caveats

Derived from CISA KEV JSON feed catalogVersion 2026.10.21. CVSS from the CVE record (cvelistV5). Exact affected/fixed version strings are not always in the KEV record; verify against the vendor advisory URL. startedAt uses dateAdded (exploitation may have begun earlier; many entries are older CVEs newly confirmed as exploited in 2025). KEV says affected products could be end-of-life, so some devices may never get a fix.