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CVE-2026-81963

Microsoft Windows•HIGH · CVSS 7.8• In the wild In CISA KEV

What is CVE-2026-81963?

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

CVSS7.8 NVD 3.1

SeverityHIGH

Exploitation In the wild In CISA KEV

EPSS<1% · P32

Triage statusActive Exploit

ActionPatch immediately

CVSS vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWECWE-59

NVD published2026-09-08

NVD last modified2026-09-09

Timeline

2026-09-08Published to the U.S. National Vulnerability Database (NVD)
2026-09-08Added to the CISA Known Exploited Vulnerabilities (KEV) catalog
2026-09-09First covered in a defend.network daily briefing
2026-09-09NVD record last updated
2026-09-22CISA federal remediation deadline (BOD 22-01)

CISA Known Exploited Vulnerability

Microsoft Windows Link Following Vulnerability

Added to KEV2026-09-08

Federal patch deadline2026-09-22

Known ransomware useUnknown

Affected product

Microsoft Windows

NVD also lists CPE entries for: Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2, Microsoft Windows 11 26h1, Microsoft Windows Server 2025

Remediation Steps

Apply the vendor security update for Microsoft Windows as a priority.
Restrict network exposure of the affected service to trusted sources until patched.
Review logs and detections for indicators of exploitation.
Confirm fixed versions against the official vendor advisory before deploying.

References

Referenced in our briefings & reports

Vulnerability Priority Report – Week 1 of September 2026 (September 7 – 13)
Microsoft, Fortra vulnerabilities patched; Warlock escalates SharePoint attacks on critical infrastructure (2026-10-04)
Fortinet FortiMail zero-day exploited; KillSec ransomware leadership dismantled (2026-10-02)
Microsoft’s record patch batch; fake LastPass installer deploys kernel EDR killer (2026-09-22)
Microsoft patches 974 CVEs; Check Point RCE; Docker Sandboxes escape on macOS (2026-09-18)
Cisco FMC actively exploited; BlueMoon exploit kit chains Chrome & Windows; AI tokens bypass MFA (2026-09-10)
Microsoft patches record 974 CVEs; AI agents steal thousands of credentials; F5 devices breached (2026-09-09)

Related vulnerabilities

CVE-2026-96951 – Microsoft Windows (same product)
CVE-2026-75682 – Adobe Connect (same product)
CVE-2026-69829 – Microsoft Windows 10 1607 (same product)
CVE-2026-85880 – Microsoft Windows (same product)
CVE-2026-68820 – Microsoft Windows Ancillary Function Driver For WinSock (same product)
CVE-2026-48449 – Adobe Campaign (same product)

Microsoft: 390 known exploited vulnerabilities (CISA KEV) →

Browse all tracked CVEs in the defend.network CVE database →

🤖 This CVE page is generated by defend.network from NVD, CISA KEV, EPSS, and our verified daily briefings. Severity and exploitation data come from official sources; always verify remediation steps against the official vendor advisory before acting in production.