Windows Update Stack Elevation of Privilege Vulnerability
Published September 8, 2026Updated September 15, 2026
Source data
Overview
Improper link resolution before file access ('link following') in Windows Update Stack allows an authorized attacker to elevate privileges locally.
Impact & technical details
Elevation of Privilege
What privileges could be gained by an attacker who successfully exploited this vulnerability? An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.
- CVSS base score
- 7.8 / 10
- CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
Highest base score supplied by MSRC for this record; the vector belongs to that score. Ratings can vary by product. Microsoft Important is displayed as High; Moderate is displayed as Medium.
Affected products
- Windows 11 Version 23H2 for ARM64-based Systems
- Windows 11 Version 23H2 for x64-based Systems
- Windows 11 Version 24H2 for ARM64-based Systems
- Windows 11 Version 24H2 for x64-based Systems
- Windows 11 Version 25H2 for ARM64-based Systems
- Windows 11 Version 25H2 for x64-based Systems
- Windows 11 Version 26H1 for ARM64-based Systems
- Windows 11 version 26H1 for x64-based Systems
Show all 10 affected products
- Windows Server 2025
- Windows Server 2025 (Server Core installation)
Source guidance
Remediation
- Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
At least one Microsoft vendor-fix reference is available. Check each affected product for its applicable update, prerequisites, and supported version.
GTP recommendation · Rule-based guidance
Recommended next step
Prioritize deployment of the available security update after appropriate compatibility validation.
Authoritative sources & updates
Findings and update information come from the linked publishers. GTP compiles the public record and provides the recommendation above. CVSS ratings shown here come from Microsoft. NVD references provide additional public context.
- Microsoft Security Response Center (opens in a new tab)
- Microsoft security update · 5122871 (opens in a new tab)
- Microsoft remediation guidance (opens in a new tab)
- Microsoft security update · 5124008 (opens in a new tab)
- Microsoft remediation guidance (opens in a new tab)
- Microsoft security update · 5122880 (opens in a new tab)
- Microsoft remediation guidance (opens in a new tab)
- Microsoft security update · 5124012 (opens in a new tab)
- Microsoft remediation guidance (opens in a new tab)
- CISA Known Exploited Vulnerabilities (opens in a new tab)
- Authoritative advisory (opens in a new tab)
- Authoritative advisory (opens in a new tab)
- Authoritative advisory (opens in a new tab)
- NIST National Vulnerability Database (opens in a new tab)
Managed by GTP?
Griffin Technology Partners managed customers may receive additional environment-specific security guidance and remediation assistance through their managed services relationship.
Security bulletins are provided for informational purposes and compiled from authoritative public sources. Vulnerability applicability varies by environment. Validate affected products, configuration, compatibility requirements, and vendor guidance before making production changes.