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Known Exploited Vulnerability
7.8
HIGH CVSS 3.1
CVE-2026-81963
Microsoft Windows Link Following Vulnerability - [Actively Exploited]
Overview
Description

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

Details
INFO

Published Date :

Sept. 8, 2026, 6:21 p.m.

Last Modified :

Sept. 9, 2026, 5:18 a.m.

Remotely Exploit :

No

Source :

[email protected]
CISA Notification
CISA KEV (Known Exploited Vulnerabilities)

For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.

Description :

Microsoft Windows Update Stack contains a link following vulnerability that allows a local attacker to escalate privileges locally up to SYSTEM.

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.

Known Ransomware Campaign Use:

Unknown

Notes :

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-81963 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-81963

Impact
Affected Products

The following products are affected by CVE-2026-81963 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Microsoft windows_11
2 Microsoft windows_11_23h2
3 Microsoft windows_11_24h2
4 Microsoft windows_server_2025
5 Microsoft windows_11_25h2
6 Microsoft windows_11_26h1
: Total Affected Vendor : 1 | Products : 6
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH [email protected]
Solution
Apply the September 2026 security updates to patch vulnerabilities.
  • Install all September 2026 security updates.
  • Verify successful update installation.
  • Reboot systems if required.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-81963.

URL Resource
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-81963 Patch Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-81963 US Government Resource
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-81963 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-81963 weaknesses.

CAPEC-17: Using Malicious Files Using Malicious Files CAPEC-35: Leverage Executable Code in Non-Executable Files Leverage Executable Code in Non-Executable Files CAPEC-76: Manipulating Web Input to File System Calls Manipulating Web Input to File System Calls CAPEC-132: Symlink Attack Symlink Attack CAPEC-19: Embedding Scripts within Scripts Embedding Scripts within Scripts CAPEC-441: Malicious Logic Insertion Malicious Logic Insertion CAPEC-478: Modification of Windows Service Configuration Modification of Windows Service Configuration CAPEC-479: Malicious Root Certificate Malicious Root Certificate CAPEC-502: Intent Spoof Intent Spoof CAPEC-503: WebView Exposure WebView Exposure CAPEC-536: Data Injected During Configuration Data Injected During Configuration CAPEC-546: Incomplete Data Deletion in a Multi-Tenant Environment Incomplete Data Deletion in a Multi-Tenant Environment CAPEC-550: Install New Service Install New Service CAPEC-551: Modify Existing Service Modify Existing Service CAPEC-552: Install Rootkit Install Rootkit CAPEC-556: Replace File Extension Handlers Replace File Extension Handlers CAPEC-558: Replace Trusted Executable Replace Trusted Executable CAPEC-562: Modify Shared File Modify Shared File CAPEC-563: Add Malicious File to Shared Webroot Add Malicious File to Shared Webroot CAPEC-564: Run Software at Logon Run Software at Logon CAPEC-578: Disable Security Software Disable Security Software

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-81963 vulnerability anywhere in the article.

  • security.nl
Microsoft dicht bijna duizend beveiligingslekken tijdens patchdinsdag september

Microsoft heeft tijdens de patchdinsdag van september bijna duizend beveiligingslekken verholpen, waaronder twee kwetsbaarheden die al voor het uitkomen van de patches werden misbruikt bij aanvallen t ... Read more

Published Date: Sep 09, 2026 (1 hour, 18 minutes ago)
  • The Cyber Express
Microsoft Patch Tuesday Hits Record 974 CVEs, Two Exploited

Microsoft’s Patch Tuesday September 2026 rollout has broken previous records, with the company addressing 974 CVEs across its product lineup in a single release. Two of these vulnerabilities were alre ... Read more

Published Date: Sep 09, 2026 (1 hour, 55 minutes ago)
  • CrowdStrike.com
September 2026 Patch Tuesday: Two Exploited Zero-Days and 113 Critical Vulnerabilities Among 972 CVEs

Microsoft has addressed 972 vulnerabilities in its September 2026 security update release, over double the number of CVEs released in August, and a new Patch Tuesday record. This month's patches inclu ... Read more

Published Date: Sep 09, 2026 (2 hours, 41 minutes ago)
  • The Hacker News
Microsoft Patches Record 974 Flaws, Including Two Exploited Windows Zero-Days

Microsoft on Tuesday broke Patch Tuesday records by addressing an earth-shattering 974 vulnerabilities spanning its software portfolio, including two flaws that it said have been actively exploited in ... Read more

Published Date: Sep 09, 2026 (4 hours, 5 minutes ago)
  • TheCyberThrone
Microsoft Patch Tuesday — September 2026

When Patch Volume Becomes a Security RiskMicrosoft’s September 2026 Patch Tuesday is not an ordinary monthly  security update.Cybersecurity Trend ReportReleased on September 8, Microsoft addressed 974 ... Read more

Published Date: Sep 09, 2026 (5 hours, 50 minutes ago)

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-81963 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Sep. 09, 2026

    Action Type Old Value New Value
    Changed SSVC {'id': 'CVE-2026-81963', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-09-08T18:44:08.999075Z'} {'id': 'CVE-2026-81963', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-09-07T00:00:00+00:00'}
  • Initial Analysis by [email protected]

    Sep. 08, 2026

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.26100.33438 *cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:* versions up to (excluding) 10.0.22631.7582 *cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:* versions up to (excluding) 10.0.22631.7582 *cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:* versions up to (excluding) 10.0.26100.9445 *cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:* versions up to (excluding) 10.0.26100.9445 *cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:* versions up to (excluding) 10.0.26200.9445 *cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:* versions up to (excluding) 10.0.26200.9445 *cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:* versions up to (excluding) 10.0.28000.2954 *cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:* versions up to (excluding) 10.0.28000.2954
    Added Reference Type Microsoft Corporation: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-81963 Types: Patch, Vendor Advisory
    Added Reference Type CISA-ADP: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-81963 Types: US Government Resource
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Sep. 08, 2026

    Action Type Old Value New Value
    Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-81963
    Changed SSVC {'id': 'CVE-2026-81963', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-09-08T17:40:01.139617Z'} {'id': 'CVE-2026-81963', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-09-08T18:44:08.999075Z'}
  • CVE CISA KEV Update by 9119a7d8-5eab-497f-8521-727c672e3725

    Sep. 08, 2026

    Action Type Old Value New Value
    Added Date Added 2026-09-08
    Added Due Date 2026-09-08
    Added Required Action 2026-09-08
    Added Vulnerability Name 2026-09-08
  • New CVE Received by [email protected]

    Sep. 08, 2026

    Action Type Old Value New Value
    Added Description Improper link resolution before file access ('link following') in Windows Update Stack allows an authorized attacker to elevate privileges locally.
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-59
    Added CWE CWE-284
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/81xxx/CVE-2026-81963.json">CVE-2026-81963</a>
    Added Reference https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-81963
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Sep. 08, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-81963', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-09-08T17:40:01.139617Z'}
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 7.8
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact