CVE-2026-81963: listed in the CISA KEV catalog

CVE-2026-81963 · CVSS 7.8 HIGH · KEV 2026-09-08 · patch available

Improper link resolution before file access ('link following') in Windows Update Stack allows an authorized attacker to elevate privileges locally.

Is CVE-2026-81963 exploited?

• Listed in the CISA KEV catalog on 2026-09-08.
• Federal remediation due 2026-09-22.
• Past that date by 37 days.
• Public exploit code: none found in monitored sources.

Which products and versions are affected?

• Microsoft · Windows 11 version 23H2 · >= 10.0.22631.0, < 10.0.22631.7582
• Microsoft · Windows 11 Version 24H2 · >= 10.0.26100.0, < 10.0.26100.9445
• Microsoft · Windows 11 Version 25H2 · >= 10.0.26200.0, < 10.0.26200.9445
• Microsoft · Windows 11 version 26H1 · >= 10.0.28000.0, < 10.0.28000.2954
• Microsoft · Windows Server 2025 · >= 10.0.26100.0, < 10.0.26100.33438
• Microsoft · Windows Server 2025 (Server Core installation) · >= 10.0.26100.0, < 10.0.26100.33438
• Microsoft · Windows 11 Version 25H2 for ARM64-based Systems
• Microsoft · Windows 11 Version 25H2 for x64-based Systems
• Microsoft · Windows 11 Version 23H2 for ARM64-based Systems
• Microsoft · Windows 11 Version 23H2 for x64-based Systems
• Microsoft · Windows 11 Version 26H1 for ARM64-based Systems
• Microsoft · Windows 11 version 26H1 for x64-based Systems

Is there a patch?

Yes. Update to one of these or later:

From Microsoft's CVE record · Microsoft advisory

• KB5122871
• KB5124008
• KB5122880
• KB5124012

From Microsoft's Security Update Guide · Microsoft advisory

What PlainSec published about CVE-2026-81963

• Microsoft's 974-fix update includes two exploited Windows flaws (2026-09-09)

Primary sources

• NVD record
• CISA KEV catalog
• Microsoft KB5122871
• Microsoft KB5124008
• Microsoft KB5122880
• Microsoft KB5124012
• Microsoft advisory

What this record does not say

• No EPSS score.

KEV and EPSS are re-checked daily. Record last updated 2026-10-23.