Incorrect default permissions in Windows Server Update Service
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- Required
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
Microsoft Windows Server 2012, 2012 R2, 2016, 2019, 2022 and 2025, including their Server Core installations, are affected before their fixed builds. Incorrect default permissions in Windows Server Update Service (CWE-276) let an authorized local attacker with low privileges gain higher privileges, and the attack requires user interaction. A successful attack fully compromises confidentiality, integrity and availability of the affected system.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
Incorrect default permissions in Windows Server Update Service allows an authorized attacker to elevate privileges locally.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Microsoft | Windows Server 2012 | 6.2.9200.0 to before 6.2.9200.26434 | 6.2.9200.26434 | Patch available | CNA |
| Microsoft | Windows Server 2012 (Server Core installation) | 6.2.9200.0 to before 6.2.9200.26434 | 6.2.9200.26434 | Patch available | CNA |
| Microsoft | Windows Server 2012 R2 | 6.3.9600.0 to before 6.3.9600.23470 | 6.3.9600.23470 | Patch available | CNA |
| Microsoft | Windows Server 2012 R2 (Server Core installation) | 6.3.9600.0 to before 6.3.9600.23470 | 6.3.9600.23470 | Patch available | CNA |
| Microsoft | Windows Server 2016 | 10.0.14393.0 to before 10.0.14393.9612 | 10.0.14393.9612 | Patch available | CNA |
| Microsoft | Windows Server 2016 (Server Core installation) | 10.0.14393.0 to before 10.0.14393.9612 | 10.0.14393.9612 | Patch available | CNA |
| Microsoft | Windows Server 2019 | 10.0.17763.0 to before 10.0.17763.9376 | 10.0.17763.9376 | Patch available | CNA |
| Microsoft | Windows Server 2019 (Server Core installation) | 10.0.17763.0 to before 10.0.17763.9376 | 10.0.17763.9376 | Patch available | CNA |
| Microsoft | Windows Server 2022 | 10.0.20348.0 to before 10.0.20348.5761 | 10.0.20348.5761 | Patch available | CNA |
| Microsoft | Windows Server 2025 | 10.0.26100.0 to before 10.0.26100.33650 | 10.0.26100.33650 | Patch available | CNA |
| Microsoft | Windows Server 2025 (Server Core installation) | 10.0.26100.0 to before 10.0.26100.33650 | 10.0.26100.33650 | Patch available | CNA |
- Windows Server 2012 VendorMicrosoft Affected 6.2.9200.0 to before 6.2.9200.26434 Fixed in 6.2.9200.26434 Patch available CNA
- Windows Server 2012 (Server Core installation) VendorMicrosoft Affected 6.2.9200.0 to before 6.2.9200.26434 Fixed in 6.2.9200.26434 Patch available CNA
- Windows Server 2012 R2 VendorMicrosoft Affected 6.3.9600.0 to before 6.3.9600.23470 Fixed in 6.3.9600.23470 Patch available CNA
- Windows Server 2012 R2 (Server Core installation) VendorMicrosoft Affected 6.3.9600.0 to before 6.3.9600.23470 Fixed in 6.3.9600.23470 Patch available CNA
- Windows Server 2016 VendorMicrosoft Affected 10.0.14393.0 to before 10.0.14393.9612 Fixed in 10.0.14393.9612 Patch available CNA
- Windows Server 2016 (Server Core installation) VendorMicrosoft Affected 10.0.14393.0 to before 10.0.14393.9612 Fixed in 10.0.14393.9612 Patch available CNA
- Windows Server 2019 VendorMicrosoft Affected 10.0.17763.0 to before 10.0.17763.9376 Fixed in 10.0.17763.9376 Patch available CNA
- Windows Server 2019 (Server Core installation) VendorMicrosoft Affected 10.0.17763.0 to before 10.0.17763.9376 Fixed in 10.0.17763.9376 Patch available CNA
- Windows Server 2022 VendorMicrosoft Affected 10.0.20348.0 to before 10.0.20348.5761 Fixed in 10.0.20348.5761 Patch available CNA
- Windows Server 2025 VendorMicrosoft Affected 10.0.26100.0 to before 10.0.26100.33650 Fixed in 10.0.26100.33650 Patch available CNA
- Windows Server 2025 (Server Core installation) VendorMicrosoft Affected 10.0.26100.0 to before 10.0.26100.33650 Fixed in 10.0.26100.33650 Patch available CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:* | r2 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:* | before 10.0.14393.9612 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:* | before 10.0.17763.9376 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:x64:* | before 10.0.20348.5761 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:* | before 10.0.26100.33650 | Vulnerable | Microsoft |
- cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:* Versions r2 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:* Versions before 10.0.14393.9612 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:* Versions before 10.0.17763.9376 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:x64:* Versions before 10.0.20348.5761 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:* Versions before 10.0.26100.33650 Vulnerable ·Microsoft
Remediation
Install the fixed builds: Windows Server 2012 and its Server Core installation 6.2.9200.26434, Windows Server 2012 R2 and its Server Core installation 6.3.9600.23470, Windows Server 2016 and its Server Core installation 10.0.14393.9612, Windows Server 2019 and its Server Core installation 10.0.17763.9376, Windows Server 2022 10.0.20348.5761, and Windows Server 2025 and its Server Core installation 10.0.26100.33650.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA Windows Server 2012 (Microsoft) Fixed in 6.2.9200.26434
- Fix · CNA Windows Server 2012 (Server Core installation) (Microsoft) Fixed in 6.2.9200.26434
- Fix · CNA Windows Server 2012 R2 (Microsoft) Fixed in 6.3.9600.23470
- Fix · CNA Windows Server 2012 R2 (Server Core installation) (Microsoft) Fixed in 6.3.9600.23470
- Fix · CNA Windows Server 2016 (Microsoft) Fixed in 10.0.14393.9612
- Fix · CNA Windows Server 2016 (Server Core installation) (Microsoft) Fixed in 10.0.14393.9612
- Fix · CNA Windows Server 2019 (Microsoft) Fixed in 10.0.17763.9376
- Fix · CNA Windows Server 2019 (Server Core installation) (Microsoft) Fixed in 10.0.17763.9376
- Fix · CNA Windows Server 2022 (Microsoft) Fixed in 10.0.20348.5761
- Fix · CNA Windows Server 2025 (Microsoft) Fixed in 10.0.26100.33650
- Fix · CNA Windows Server 2025 (Server Core installation) (Microsoft) Fixed in 10.0.26100.33650
Timeline
- 2026-10-13 Threatist record created from CVE-2026-105009
- 2026-10-13 CISA SSVC decision points changed
- 2026-10-13 Priority changed: MEDIUM → LOW
- 2026-10-13 Alias added: GHSA-455h-gjpq-v2gc
- 2026-10-18 CISA SSVC decision points changed
References
More Microsoft Windows Server 2012 vulnerabilities
- TI-2025-36863 Windows Server Update Service (WSUS) Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
- TI-2020-01431 Netlogon Elevation of Privilege Vulnerability KEVCVSS 3.1CRITICAL 10.0
- TI-2020-01310 Improper input validation in Microsoft Windows Server KEVCVSS 3.1CRITICAL 10.0
- TI-2017-06077 Microsoft Windows XP SP3, Windows XP x64 XP2, Windows Server 2003 SP2, Windows Vista… KEVCVSS 3.1CRITICAL 9.8
- TI-2015-01465 HTTP.sys in Microsoft Windows 7 SP1, Windows Server 2008 R2 SP1, Windows 8, Windows 8.1… KEVCVSS 3.1CRITICAL 9.8
- TI-2020-01009 Improper input validation in Microsoft Windows Server KEVCVSS 3.1CRITICAL 9.0
Sources
- CVE-2026-105009 · CVE Program
- CVE-2026-105009 · NVD
- FIRST EPSS
- GHSA-455h-gjpq-v2gc · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences