Microsoft’s final Patch Tuesday of 2025 introduces 57 security fixes across Windows, Office, Azure Monitor Agent, SharePoint, RRAS, and a wide range of filesystem and driver components.
One vulnerability has confirmed active exploitation (CVE-2025-62221), and several others are rated as more likely to be exploited, which increases the urgency for security teams managing Windows desktops and servers.
Although this month does not include any CVSS scores above 8.8, the combination of local privilege escalation paths, document-based attack vectors, and exposed remote access services creates a meaningful operational risk for most environments.
This article outlines the most important vulnerabilities to evaluate, the items that require rapid deployment, and the practical steps IT teams should follow to stay protected.
Microsoft Patch Overview
This month’s release contains 57 Microsoft vulnerabilities and 13 republished Chromium CVEs for Microsoft Edge. The update set concentrates on areas that tend to produce real-world impact when left unpatched. These include Windows filesystem and storage layers, kernel-adjacent drivers, Office document processing, RRAS and other remote access components, and Azure Monitor Agent.
The highest CVSS ratings reach 8.8, consistent with Microsoft’s recent trend of elevating risk not through extreme severity scores but through a broad attack surface and attack chains that can lead to privilege escalation or remote code execution.
Administrators should note the density of elevation-of-privilege issues affecting storage drivers, cloud file sync mechanisms, and log file system components. These weaknesses often serve as building blocks for post-exploitation activity. The Office and Outlook vulnerabilities also deserve close attention since crafted documents and message previews remain reliable entry points for threat actors.
Together, these themes reinforce the importance of rapid assessment after each Patch Tuesday and a structured patch deployment strategy that reduces dwell time on endpoints.
Zero Day and Exploitation Likely Vulnerabilities
Actively Exploited Zero Day
CVE-2025-62221 affects the Windows Cloud Files Mini Filter Driver and is confirmed as exploited in the wild. The flaw allows a local attacker to escalate privileges, which makes it useful during lateral movement or persistence phases once an adversary has already gained a foothold. Systems that rely on cloud file sync features or environments with frequent user privilege transitions are particularly exposed. This issue should be prioritized across all supported Windows versions, including servers that host user profile redirection or file synchronization workloads.
Vulnerabilities With Higher Likelihood of Exploitation
Microsoft has also classified several additional vulnerabilities as more likely to be exploited. While these have not been observed in active attacks, they represent conditions that adversaries commonly target. These include:
Windows Storage VSP Driver (CVE-2025-59516 and CVE-2025-59517)
Windows Cloud Files Mini Filter (CVE-2025-62454)
Windows Win32K GRFX (CVE-2025-62458)
Windows Common Log File System Driver (CVE-2025-62470)
Windows Remote Access Connection Manager (CVE-2025-62472)
Each of these vulnerabilities carries a 7.8 CVSS rating and affects foundational Windows components. Storage and driver-level flaws are often weaponized for privilege escalation, while issues in remote access services can influence authentication paths or connectivity controls. These items should be handled immediately after the confirmed zero day and incorporated into the first wave of patch deployment for this cycle.
Critical Vulnerabilities
This section highlights the most impactful vulnerabilities from the December release. While none reach a CVSS score of 9.0 or higher, several offer meaningful opportunities for remote code execution or affect components that are common entry points in enterprise environments. These issues represent the highest functional risk this month and should be reviewed before building patch deployment schedules.
Office Remote Code Execution
Two Microsoft Office vulnerabilities stand out due to their ability to trigger code execution through crafted documents.
CVE-2025-62554
CVE-2025-62557
Both issues can be reached through typical document workflows. Organizations with employees who regularly receive external files or who rely heavily on shared document libraries should consider these high priority.
Outlook Remote Code Execution
The Outlook vulnerability tracked as CVE-2025-62562 introduces a direct messaging vector for code execution. Attackers may use specially formed messages or attachments to trigger this issue. Any environment with executive users, help desk queues, or shared mailboxes faces elevated exposure since these accounts often process high volumes of inbound content.
High Severity CVSS 8.8 Cases
Several vulnerabilities rank at the top of this month’s scoring and affect critical infrastructure components.
Windows Resilient File System (ReFS)
Windows Routing and Remote Access Service (RRAS)
Azure Monitor Agent
Microsoft Office SharePoint
These components play a central role in storage reliability, remote connectivity, monitoring pipelines, and collaborative workloads. A compromise in any of these areas can disrupt operations, enable unauthorized access, or expose sensitive business data. Even though these issues do not carry the “Critical” label by CVSS alone, they warrant the same urgency due to their potential blast radius and the prevalence of these services in production environments.
Patch Prioritization Guidance
Patch Within 72 Hours
Focus this first window on vulnerabilities that introduce immediate risk or are likely to be exploited soon.
Actively exploited
CVE-2025-62221 Windows Cloud Files Mini Filter Driver Privilege escalation confirmed in the wild. Highest urgency this month.
Exploitation more likely
CVE-2025-59516 Windows Storage VSP Driver
CVE-2025-59517 Windows Storage VSP Driver
CVE-2025-62454 Windows Cloud Files Mini Filter
CVE-2025-62458 Windows Win32K GRFX
CVE-2025-62470 Windows Common Log File System
CVE-2025-62472 Windows Remote Access Connection Manager
High severity vulnerabilities (CVSS 8.0 to 8.8)
CVE-2025-62456 Windows ReFS
CVE-2025-62549 Windows RRAS
CVE-2025-64678 Windows RRAS
CVE-2025-62550 Azure Monitor Agent
CVE-2025-64672 Microsoft Office SharePoint
CVE-2025-62554 Microsoft Office
CVE-2025-62557 Microsoft Office
CVE-2025-62562 Microsoft Outlook
CVE-2025-64671 Copilot
Patch Within One to Two Weeks
Apply these updates after your 72-hour set has rolled out and been validated.
Filesystem and driver EoPs
CVE-2025-55233 Projected File System
CVE-2025-62461 Projected File System
CVE-2025-62462 Projected File System
CVE-2025-62464 Projected File System
CVE-2025-62467 Projected File System
CVE-2025-62457 Cloud Files Mini Filter
CVE-2025-62466 Client-Side Caching
CVE-2025-62469 Brokering File System
CVE-2025-62569 Brokering File System
CVE-2025-64673 Storvsp.sys
Windows platform services
CVE-2025-54100 PowerShell
CVE-2025-62565 Windows Shell
CVE-2025-64658 Windows Shell
CVE-2025-64661 Windows Shell
CVE-2025-62570 Camera Frame Server Monitor
CVE-2025-62571 Windows Installer
CVE-2025-62572 Application Information Services
CVE-2025-62573 DirectX
Office and productivity
CVE-2025-62552 Access
CVE-2025-62553 Excel
CVE-2025-62556 Excel
CVE-2025-62560 Excel
CVE-2025-62561 Excel
CVE-2025-62563 Excel
CVE-2025-62564 Excel
CVE-2025-62555 Word
CVE-2025-62558 Word
CVE-2025-62559 Word
CVE-2025-62562 Outlook
Server-side components
CVE-2025-64666 Exchange Server
Add to Regular Patch Cadence
These vulnerabilities carry lower severity or are rated as unlikely to be exploited. Patch them after higher-priority updates are deployed.
Examples include:
CVE-2025-62468 Windows Defender Firewall Service
CVE-2025-62567 Windows Hyper-V
CVE-2025-64667 Exchange Server
CVE-2025-62463 DirectX
CVE-2025-62465 DirectX
CVE-2025-62473 RRAS
CVE-2025-64670 Graphics Component
Next Steps for IT and Security Teams
After deploying the initial patches, teams should take several follow-up actions to confirm coverage, reduce residual risk, and prepare systems for the next maintenance cycle. These steps help ensure that updates are not only installed but also functioning as intended across diverse environments.
1. Validate successful deployment
Confirm that high-priority patches are applied to all Windows workstations and servers.
Pay particular attention to systems that manage storage operations, cloud file synchronization, and remote access services.
Review logs for installation failures or endpoints that missed the update window.
2. Review exposure for high-risk user groups
Verify patch status for executive accounts, administrators, developers, and support teams.
These users are more likely to interact with document or messaging workflows that can trigger Office and Outlook vulnerabilities.
3. Evaluate system behavior and performance
Monitor event logs, stability metrics, and application behavior after deployment.
Check for issues with file system components since many changes this month affect drivers and storage layers.
4. Confirm visibility and asset coverage
Ensure that all managed devices, including remote or hybrid endpoints, check in with your patching platform.
Update inventory records to reflect newly patched components and identify any unmanaged systems that require manual attention.
5. Strengthen automation for future patch cycles
Use insights from this month’s rollout to refine automation rules and patching policies.
Prioritize reducing manual touchpoints since many of the vulnerabilities this month highlight the impact of delayed remediation.
These steps help teams maintain a stable environment while reducing the opportunity for attackers to exploit newly disclosed vulnerabilities.
How Splashtop AEM Supports Faster Remediation
Many teams face delays during Patch Tuesday cycles because their tools require long check-in intervals, lack real-time visibility, or provide limited automation. Splashtop AEM helps reduce those gaps so that organizations can respond to issues like the Cloud Files Mini Filter vulnerabilities, Office RCE risks, or RRAS exposures without extended remediation windows.
Real-time patching across Windows and macOS
Splashtop AEM allows administrators to deploy updates immediately rather than waiting for scheduled refresh cycles. This is particularly useful for vulnerabilities that require rapid action, such as privilege-escalation flaws in storage and file-system drivers.
CVE-level visibility and impact assessment
Splashtop AEM maps vulnerabilities to affected devices and software versions. Teams can quickly identify which endpoints contain vulnerable components such as ReFS, Azure Monitor Agent, or Office applications. This helps prioritize systems that require attention during the first 72 hours.
Policy-driven automation
Automation policies reduce manual effort and ensure updates are applied consistently. Administrators can create rules for high-severity cases, schedule phased rollouts, or configure maintenance windows that avoid business disruption. This approach improves reliability and strengthens patch compliance.
Comprehensive hardware and software inventory
Splashtop AEM provides a unified view of installed applications, operating system versions, and active services. This simplifies the process of verifying exposure and validating successful remediation for components like RRAS, cloud file filters, or DirectX drivers.
Lightweight architecture suitable for varied IT environments
Organizations that rely on manual patching, Intune, or traditional RMM tools can use Splashtop AEM to close functional gaps. Intune users gain faster patch execution and broader third-party coverage. Teams using complex RMM products gain a simpler and more flexible alternative that still supports scripting, configuration policies, dashboards, and ring-based deployment strategies.
Strengthen Your Patch Strategy and Start a Splashtop AEM Free Trial
December’s update cycle includes a concentrated set of privilege escalation paths, Office and Outlook RCE vectors, and high-impact service vulnerabilities. Fast and consistent remediation is essential for reducing exposure, especially when attackers tend to target newly disclosed issues within days. Splashtop AEM provides real-time patching, automation policies, and clear CVE visibility that help teams close these gaps with less manual effort.
If you want to streamline future Patch Tuesday cycles and improve endpoint security posture, start a free trial of Splashtop AEM today.
