Critical Security Vulnerabilities
Type:
Elevation of Privilege (Use-After-Free)
Impact:
Allows a local authenticated attacker to gain SYSTEM privileges. This driver is core to Windows (used by OneDrive, iCloud, etc.), making the attack surface very wide.
Risk Assessment:
HIGH. Confirmed active exploitation in the wild. Attacker requires local access, but this is a standard step in infection chains (e.g., after phishing) to gain full control.
Affected Systems:
Windows 10, Windows 11, Windows Server 2016-2025.
Type:
Remote Code Execution (Use-After-Free)
Impact:
An attacker can execute malicious code by sending a specially crafted email. Microsoft states the Preview Pane is not an attack vector (unlike some past Outlook bugs), but opening the item triggers it.
Risk Assessment:
CRITICAL. RCE in Outlook is always high priority. While Preview Pane is safe, user interaction (opening email) is easy to engineer.
Type:
Remote Code Execution (Type Confusion)
Impact:
Similar to the Outlook flaw, this allows code execution via malicious Office documents. The Preview Pane IS an attack vector for this vulnerability.
Risk Assessment:
CRITICAL. Zero-click potential via Preview Pane makes this extremely dangerous for organizations relying on Office desktop apps.
Windows Server & Enterprise Vulnerabilities
Affected CVEs:
CVE-2025-55182
Impact:
While technically a framework vulnerability, this affects Windows Servers hosting Next.js/React applications. It allows unauthenticated remote code execution via React Server Function endpoints.
Risk Assessment:
MAXIMUM. If you host internal web apps using React/Next.js on Windows Server, audit them immediately.
Type:
Elevation of Privilege
Impact:
Improper input validation allows an authenticated low-privilege attacker to elevate privileges over the network.
Risk Assessment:
HIGH. While Microsoft lists exploitation as "less likely," Exchange vulnerabilities are a favorite target. View MSRC Advisory
Type:
Spoofing
Impact:
Allows an attacker to perform spoofing over the network due to user interface misrepresentation.
Risk Assessment:
MEDIUM. View MSRC Advisory
Type:
Remote Code Execution (Command Injection)
Impact:
Allows unauthorized attacker to execute code remotely. The update adds a confirmation prompt to Invoke-WebRequest to mitigate risk.
Affected Versions:
Windows Server 2008 through Server 2025.
Risk Assessment:
HIGH. Publicly disclosed before patch, increasing risk of weaponization. The behavior change in Invoke-WebRequest may break some automated scripts.
Type:
Command Injection
Impact:
Affects the Copilot plugin for JetBrains. An attacker can trick the LLM into running malicious commands if "auto-approve" is enabled.
Risk Assessment:
MEDIUM/HIGH. Relevant for DevSecOps environments. Publicly disclosed.
⚠️ Critical Third-Party Advisory
Type:
Authentication Bypass (Improper Verification of Cryptographic Signature)
Impact:
An unauthenticated attacker can bypass FortiCloud SSO login via crafted SAML messages. Affects FortiOS, FortiProxy, FortiWeb, and more.
Risk Assessment:
CRITICAL. Ensure your edge devices are patched or the FortiCloud SSO feature is disabled. View Fortiguard Advisory
Available Updates by Platform
🪟 Windows 11
| Version | Knowledge Base | Build Number | Status |
|---|---|---|---|
| 24H2 & 25H2 | KB5072033 | 26100.7462 / 26200.7462 | Released |
| 22H2 & 23H2 | KB5071417 | 22631.6345 | Released |
🖥️ Windows Server
| Version | Knowledge Base | Build Number | Priority |
|---|---|---|---|
| Server 2025 | KB5072033 | 26100.7462 | P1 - Critical |
| Server 2022 | KB507203X | 20348.xxxx | P1 - Critical |
💻 Windows 10
| Version | Knowledge Base | Status | Notes |
|---|---|---|---|
| 22H2 | KB5072653 | P1 - Critical | Includes fixes for ESU enrollment failures (error 0x800f0922). |
✨ Notable Quality-of-Life & Bug Fixes
Beyond security, this update addresses several nagging functional issues:
- Hyper-V Fix: Resolves issue where external virtual switches lost NIC bindings after reboot.
- AMD Fix: Addresses GPU hangs affecting recent titles like Battlefield 6.
- Taskbar: Fixed auto-hide reliability issues.
Installation & Known Issues
⚠️ Reported Issues (December 2025)
Recommended Workarounds:
- Invisible Buttons: Hovering the mouse over the area where the button should be makes it clickable. Microsoft is deploying a Known Issue Rollback (KIR).
- Install Failures (Win10): If KB5072653 fails with 0x800f0922, verify your ESU license key status and ensure adequate partition space.
📋 Outstanding Known Issues (Per Microsoft)
1. Outlook Attachment Error
Some users on the "New Outlook" client are unable to open Excel attachments. Microsoft is rolling out a cloud-side fix.
2. PowerShell Script Warning
Not a bug, but a breaking change: Invoke-WebRequest now prompts for confirmation to prevent script execution. This will break non-interactive scripts using this cmdlet without the -UseBasicParsing switch or proper handling.
Community Feedback from Major Sites & Boards
🌐 BornCity.com (Günter Born)
Assessment: Cautious. Highlights the "invisible password button" as a major annoyance for end-users.
- Confirmed the User Account Control (UAC) prompts appearing randomly for some users has been addressed.
- Notes that the "End of Support" for Win 11 23H2 Home/Pro is now effectively in force; users must upgrade to 24H2.
📰 Ghacks.net (Martin Brinkmann)
Assessment: Critical of the UI glitches.
- "Not one bit surprised that Microsoft can't fix their s***" regarding the Dark Mode flashes.
- Emphasizes the importance of the Chrome/Edge updates bundled (CVE-2025-13630 range) for browser security.
🤖 r/sysadmin (Reddit Patch Tuesday Megathread)
Assessment: Focused on the "React2Shell" and PowerShell changes.
- Admins are scrambling to check if internal apps use the vulnerable Next.js versions (CVE-2025-55182).
- Discussions about the Cloud Files driver (CVE-2025-62221) being a "must-patch" because it affects almost every machine (OneDrive/SharePoint usage).
- Confusion regarding the simplified Windows Update titles (e.g., removing architecture labels).
🇩🇪 Administrator.de
Assessment: Technical discussion on Server 2025.
- Users discussing the specific mix of updates for Server 2022 vs 2025.
- Some reports of slow install times on Server 2019.
Deployment & Implementation Guide
🎯 Priority 1 - Deploy Immediately (After Testing)
| CVE | Vulnerability | Reason | Timeline |
|---|---|---|---|
| CVE-2025-62221 | Cloud Files Mini Filter | Actively Exploited Local Priv-Esc | 48 hours |
| CVE-2025-62554 | Office RCE | Preview Pane Vector (Zero-Click) | 48 hours |
🎯 Priority 2 - Deploy Within 7 Days
- PowerShell Update: Test scripts for the new
Invoke-WebRequestprompt behavior before rolling out. - Browser Updates: Edge/Chrome updates (fixing V8 engine flaws) should be pushed.
🧪 Testing Checklist
- Script Automation: Verify no scheduled tasks are hanging on the new PowerShell prompt.
- Hyper-V Networking: Reboot hosts to ensure NIC bindings persist (verifying the fix works).
- Lock Screen: Check a sample of laptops for the "invisible password button" issue.
🔄 Rollback Planning
📊 Deployment Tracking
cldflt.sys (Cloud Filter driver) active and ensure they report a version greater than the December baseline.