CVE-2026-81963

HIGH7.8

CISA KEV

Published 2026-09-08 · Updated 2026-09-09 · Source secure@microsoft.com

Summary

CVE-2026-81963 is a high-severity (CVSS 7.8) vulnerability in Microsoft Windows. CISA added it to the Known Exploited Vulnerabilities catalog on September 8, 2026, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by September 22, 2026. CISA does not currently list it as used in ransomware campaigns. Microsoft has 390 vulnerabilities in the KEV catalog, 117 of them linked to ransomware.

All 390 known-exploited Microsoft vulnerabilities →

Description

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

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

CWE-59CWE-284

CISA Known-Exploited Vulnerability

Product: Microsoft — Windows

Name: Microsoft Windows Link Following Vulnerability

Date added: 2026-09-08 · Due: 2026-09-22

Required action: 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.

References

View on NVD

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