What’s Vulnerable › Vulnerabilities

CVE-2026-81963: Microsoft Windows Link Following Vulnerability

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: yes — in CISA KEV since 2026-09-08
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-08 · updated 2026-09-09
• Weakness: CWE-59

Description

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

Affected products

• Microsoft Windows 11: before 10.0.22631.7582 — fixed in 10.0.22631.7582
• Microsoft Windows 11: before 10.0.26100.9445 — fixed in 10.0.26100.9445
• Microsoft Windows 11 25H2: before 10.0.26200.9445 — fixed in 10.0.26200.9445
• Microsoft Windows 11 version 26H1: before 10.0.28000.2954 — fixed in 10.0.28000.2954
• Microsoft Windows Server 2025: before 10.0.26100.33438 — fixed in 10.0.26100.33438

How to fix

Upgrade to a fixed version: Microsoft Windows 11 10.0.22631.7582; Microsoft Windows 11 10.0.26100.9445; Microsoft Windows 11 25H2 10.0.26200.9445; Microsoft Windows 11 version 26H1 10.0.28000.2954; Microsoft Windows Server 2025 10.0.26100.33438. Check the vendor advisory for mitigations.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-81963
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-81963

Get alerted when CVE-2026-81963 or the next vulnerability affects your stack