CVE-2026-81963: Microsoft Windows Link Following Vulnerability

CISA Known Exploited Vulnerabilities

Name

Microsoft Windows Link Following Vulnerability

Vendor

Microsoft

Product

Windows

Added to the catalog

2026-09-08

Due date for US federal agencies

2026-09-22

Weaknesses

CWE-59, CWE-284

Catalog version

2026.10.30

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

Required action (CISA)

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.

Ransomware use: CISA does not mark known use of this vulnerability in ransomware campaigns.

Links in CISA's notes

• https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-81963
• https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
• 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

Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

NVD analysis

Status

Analyzed

Published

2026-09-08T18:21:00.090

Last modified

2026-09-09T05:18:17.173

Weaknesses

CWE-59, CWE-284

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

References

• 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)

This product uses the NVD API but is not endorsed or certified by the NVD.

Read on 2026-11-02T23:42:31.494Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-81963

CVE record

Title (CNA)

Windows Update Stack Elevation of Privilege Vulnerability

Assigner

microsoft

State

PUBLISHED

Published

2026-09-08T17:19:13.121Z

Updated

2026-10-31T16:17:44.501Z

Problem types

CWE-59: Improper Link Resolution Before File Access ('Link Following'); CWE-284: Improper Access Control

References

• Windows Update Stack Elevation of Privilege Vulnerability

Read on 2026-11-03T02:21:14.865Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/81xxx/CVE-2026-81963.json

Defensive techniques (MITRE D3FEND)

D3FEND maps these defensive techniques to the weakness (CWE) that NVD lists for this CVE, through the digital artifacts the weakness affects. D3FEND does not say they stop this vulnerability.

MITRE D3FEND™ knowledge graph. © 2025 The MITRE Corporation.
"The MITRE Corporation (MITRE) hereby grants you a non-exclusive, royalty-free license to use D3FEND for research, development, and commercial purposes. Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." Terms: https://d3fend.mitre.org/tou/