Local privilege escalation via improper link resolution
Published Sep 8, 2026 · Updated Sep 9, 2026
Improper link resolution in Microsoft Windows Update Stack allows local users with low privileges to gain SYSTEM privileges. The stack follows an attacker-controlled link before file access without enforcing the intended access boundary. A local low-privilege foothold is required; no user interaction is needed, and successful exploitation grants full control of the affected host.
Summary
What happened
Improper link resolution in Microsoft Windows Update Stack allows local users with low privileges to gain SYSTEM privileges. The stack follows an attacker-controlled link before file access without enforcing the intended access boundary. A local low-privilege foothold is required; no user interaction is needed, and successful exploitation grants full control of the affected host.
The record
- CVE
- CVE-2026-81963
- Published
- Sep 8, 2026
- Updated
- Sep 9, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2025 (Server Core installation)
- Classifications
- CWE-59, CWE-284, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 8, 2026Exploitation reportedCISA Known Exploited Vulnerabilities Catalog listing
- Sep 8, 2026CVE publishedPublication date reported by the CVE source.
- Sep 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.26100.0 <10.0.26100.33438
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- CISA Known Exploited Vulnerabilities Catalog listingknown exploited catalog
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo