Windows Ecosystem Bulletins & Field News

Welcome to the Windows Ecosystem Bulletins & Field News stream. This live chronological journal compiles verified Microsoft cumulative updates, Patch Tuesday zero-day disclosures, Windows Server operational advisories, and enterprise Active Directory developments.

All bulletins include official source attribution, publication timestamps, and actionable remediation steps.

Latest AdvisoryPatch Tuesday Zero-Day🏛️ Source: Microsoft MSRC & CISA KEV

📅 Published: September 15, 2026

🪟 Windows September 2026 Patch Tuesday Zero-Days: ALPC & Update Stack Privilege Escalations (CVE-2026-85880 & CVE-2026-81963)

CVSS 7.8 ImportantCISA KEV ListedActive Zero-Days

In the historic September 2026 Patch Tuesday release, Microsoft resolved two actively exploited zero-day Elevation of Privilege (EoP) flaws:

CVE-2026-85880: A heap buffer overflow in the Windows Advanced Local Procedure Call (ALPC) component, allowing local low-privilege attackers to break sandbox barriers and elevate to NT AUTHORITY\SYSTEM.
CVE-2026-81963: An improper link resolution (“link following”) defect in the Windows Update Stack, enabling local attackers to abuse SYSTEM write privileges and plant arbitrary binaries.

Both vulnerabilities were immediately added by CISA to the Known Exploited Vulnerabilities catalog.

📖 Read Full Bulletin & Verification Scripts (PowerShell Hotfix Audit & Update Stack Integrity)Click to Expand ↓

Step 1: Verify Installed Windows Cumulative Updates via PowerShell

Audit Installed Windows Cumulative KBs Across Fleet

PowerShell Audit

Verify that the September 2026 cumulative servicing updates are installed across your endpoint fleet:

# Retrieve recent Cumulative Updates and hotfix IDs:
Get-HotFix | Where-Object { $_.Description -match 'Security Update|Update' } |
    Sort-Object -Property InstalledOn -Descending |
    Select-Object -First 5 -Property HotFixID, Description, InstalledOn, InstalledBy |
    Format-Table -AutoSize

Step 2: Audit Windows Update Stack Servicing Health

Verify Windows Servicing Stack Health via DISM

Servicing Health

Inspect the Component-Based Servicing (CBS) store to ensure no broken update stack junctions exist:

# Run component store health check:
dism.exe /Online /Cleanup-Image /ScanHealth

Feature UpdateWindows 11🏛️ Source: Windows IT Pro Blog

📅 Published: September 29, 2026

🪟 Windows 11 Version 26H2 Release, JIT Administrator Protection & Server 2025 RDS Hotfixes

Feature Update 26H2Server 2025 RDSJIT Elevation

On September 29, 2026, Microsoft officially released Windows 11 Version 26H2 (the Windows 11 2026 Update). Delivered primarily as a lightweight enablement package (KB5121794) for devices on previous annual baselines, the update introduces major enterprise system security changes.

At the same time, sysadmins managing enterprise fleets face critical operational updates: Microsoft released emergency out-of-band updates (KB5129235) for Windows Server 2025 to resolve severe Remote Desktop Services (RDS) server crashes caused by the September cumulative patch, alongside the formal deprecation announcement of the legacy Windows Deployment Services (WDS) role.

📖 Read Full Bulletin & Deployment Scripts (RDS Hotfix, JIT Elevation & WDS Audit)Click to Expand ↓

Step 1: Deploy Emergency Out-of-Band Hotfix for Windows Server 2025 RDS

Mitigate Remote Desktop Session Crashes on Terminal Servers

Server Fix

If your Windows Server 2025 RDS session hosts experience frozen sessions or authentication deadlocks following September updates, deploy hotfix KB5129235:

# Check if the emergency RDS hotfix is already installed on the session host:
Get-HotFix -Id KB5129235 -ErrorAction SilentlyContinue

# Restart TermService Remote Desktop Services broker cleanly if experiencing connection deadlocks:
Get-Service -Name TermService | Restart-Service -Force

Step 2: Audit Just-In-Time Administrator Protection Status

Inspect JIT Administrator Protection Token Policies

Security Baseline

In 26H2, continuous admin privileges are replaced with isolated tokens. Verify the local security policy enforcement:

# Query Local Security Authority (LSA) configuration for Administrator Protection:
Get-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Control\Lsa" -Name "AdminProtection" -ErrorAction SilentlyContinue

# Verify User Account Control token elevation behavior:
Get-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System" -Name "ConsentPromptBehaviorAdmin"

Security AdvisoryActive KEV🏛️ Source: CISA KEV & Microsoft MSRC

📅 Published: September 25, 2026

🪟 Microsoft SharePoint Server Authenticated Remote Code Execution (CVE-2026-65660)

CVSS 8.8 HighCISA KEV ListedActive Exploit

Added to CISA KEV on September 25, 2026: A code injection defect in Microsoft SharePoint Server allows authenticated users with standard site member privileges to trigger server-side code execution in the context of the SharePoint application pool worker process (w3wp.exe).

📖 Read Full Bulletin & SharePoint Farm Audit CommandsClick to Expand ↓

Step 1: Verify SharePoint Farm Patch Level via PowerShell

Check SharePoint Cumulative Update Build Number

SharePoint Farm

Connect to the SharePoint Central Administration server and verify the farm build version:

# Query SharePoint local farm build release:
Add-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue
(Get-SPFarm).BuildVersion