Microsoft December Patch Tuesday Addresses Multiple Actively Exploited Vulnerabilities
Microsoft released its December Patch Tuesday updates, addressing a total of 57 CVEs, including several critical vulnerabilities that have been actively exploited. Among the most notable is CVE-2025-62221, a Windows Cloud Files Mini Filter Driver flaw rated 7.8 on the CVSS scale, which allows local privilege escalation if an attacker already has code execution on the system. Microsoft confirmed this vulnerability is being exploited as a zero-day, underscoring the urgency for organizations to apply the patch. Additional high-severity vulnerabilities include a PowerShell Remote Code Execution flaw (CVE-2025-54100) and a GitHub Copilot for Jetbrains bug (CVE-2025-64671), both of which are publicly known but not yet observed in active exploitation.
Separately, Microsoft also issued a fix for CVE-2025-9491, a high-severity vulnerability in Windows LNK files that has been actively exploited by both state-sponsored and cybercriminal groups. This flaw enables attackers to embed malicious commands in shortcut files, facilitating malware deployment and persistent access to compromised systems. Security experts emphasize the importance of prioritizing these patches, as the vulnerabilities are being leveraged in real-world attacks and could lead to significant compromise if left unaddressed.
Timeline
Dec 9, 2025
Microsoft releases December Patch Tuesday updates
Microsoft issued patches for 57 CVEs in its December 2025 Patch Tuesday release. The update included fixes for one actively exploited zero-day, CVE-2025-62221, a local privilege escalation flaw in the Windows Cloud Files Mini Filter Driver.
Dec 9, 2025
Notepad++ releases v8.8.9 to fix exploited updater flaw
Notepad++ published version 8.8.9 to remediate a critical updater vulnerability that attackers in China had been exploiting to hijack update traffic and deliver malware. The release was highlighted alongside other December 2025 security fixes.
Dec 9, 2025
Ivanti fixes critical Endpoint Manager XSS vulnerability
Ivanti patched CVE-2025-10573, a critical cross-site scripting flaw in Endpoint Manager that could enable remote code execution and session hijacking. Researchers warned that exploitation could let attackers compromise all managed endpoints, though no active attacks were reported at disclosure.
Dec 9, 2025
Fortinet patches two critical authentication bypass flaws
Fortinet released fixes for CVE-2025-59718 and CVE-2025-59719, two critical authentication bypass vulnerabilities affecting multiple products when FortiCloud SSO login is enabled. The issues were disclosed as part of the December 2025 patch cycle.
Nov 1, 2025
Microsoft fixes exploited Windows LNK vulnerability in November updates
Microsoft addressed CVE-2025-9491 in its November 2025 security updates by changing LNK file behavior to block the shortcut-file abuse technique. The patch followed reports of active exploitation by multiple threat actors.
Nov 1, 2025
Multiple threat groups exploit Windows LNK flaw CVE-2025-9491
At least 11 state-sponsored and cybercriminal groups, including Evil Corp, Bitter, APT37, APT43, Mustang Panda, SideWinder, RedHotel, and Konni, exploited CVE-2025-9491 in Windows LNK files to hide malicious commands and deliver malware such as Ursnif, Gh0st RAT, Trickbot, and PlugX RAT. The flaw enabled stealthy malware deployment and persistence through padded shortcut Target fields.
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