← All Advisories

Microsoft Windows' Improper Link Resolution Before File Access Allows a Local Attacker to Follow Symbolic Links to Privileged Files and Gain Elevated Access; CISA's September 22nd KEV Deadline Has Passed

Last refreshed2026-09-27

Status: KEV  |  Advisory ID: CVE-2026-81963

Key Details

CVECVE-2026-81963
Vulnerability NameMicrosoft Windows Link Following Vulnerability
CVSS Score / Version7.8 (High) / CVSS v3.1
Updated2026-09-20
CVSS VectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS Proseattack vector is local; attack complexity is low; privileges required is low; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is high; availability impact is high.
Affected productssee table below
Exploitation statusListed in CISA's Known Exploited Vulnerabilities (KEV) catalog, indicating confirmed active exploitation.
Classified asCWE-59 (Improper Link Resolution Before File Access ('Link Following'))
KEV listingAdded to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-09-08.
Exploitation prediction (EPSS)0.39% probability of exploitation in the next 30 days (31% percentile) -- FIRST.org's EPSS model.
Federal remediation deadline2026-09-22 (CISA KEV, Binding Operational Directive).

Affected Products, Subsystems & Sectors

VendorProductAffected VersionsPatch Status
MicrosoftWindows
MicrosoftWindows 11 (version 23H2)
MicrosoftWindows 11 (version 24H2)
MicrosoftWindows 11 (version 25H2)
MicrosoftWindows 11 (version 26H1)
MicrosoftWindows Server 2025
SubsystemsCore Infrastructure, EWS Workstation Delivery/Virtualization
SectorsAll Sectors

What to Know

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

What to Do

Monitor Microsoft's web page for any future patch releases. See vendor advisory link below.

References

SourceReference
NVDhttps://nvd.nist.gov/vuln/detail/CVE-2026-81963
CVEhttps://www.cve.org/CVERecord?id=CVE-2026-81963
Vendor advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-81963

KEV Required Action

FieldValue
KEV Linkhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog
Date Added to KEV2026-09-08
Required Action Due Date2026-09-22
Required ActionApply 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.

About

OT-Advisories  ·  CVE  ·  NVD  ·  CVSS  ·  KEV  ·  EPSS  ·  CWE