Which products and versions are affected by CVE-2026-81963?

Affected: windows 11 23H2 (Microsoft) versions 10.0.22631.7582; windows 11 24H2 (Microsoft) versions 10.0.26100.9445; windows 11 25H2 (Microsoft) versions 10.0.26200.9445, among others. The full list is in the CVE brief.

Is CVE-2026-81963 being exploited in the wild?

It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Sep 8, 2026.

Is CVE-2026-81963 in the CISA KEV catalog?

Yes. It was added on Sep 8, 2026 with a federal remediation due date of Sep 22, 2026.

Is there a public exploit for CVE-2026-81963?

Public exploit code is available.

How urgently should CVE-2026-81963 be patched?

Brandefense priority: patch immediately, because it is listed as exploited in the wild.

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Vulnerability Intelligence

CVE-2026-81963

HighExploitedPublic exploit

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

Published Sep 8, 2026 · Updated Oct 14, 2026 · Also known as EUVD-2026-73889, GHSA-4j4j-2wjq-mxqj

Key Facts

Patch immediately

CVE-2026-81963 is a high-severity vulnerability (CVSS 7.8 v3.1) affecting windows 11 23H2 (Microsoft), windows 11 24H2 (Microsoft), windows 11 25H2 (Microsoft) and 7 more products.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Sep 8, 2026. Public exploit code is available.
EPSS estimates a 0.4% probability of exploitation in the next 30 days.
Fixed versions are available, including windows 11 23H2 10.0.22631.7582, windows 11 24H2 10.0.26100.9445, windows 11 25H2 10.0.26200.9445.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.

CVSS v3.1

7.8

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C

EPSS (30-day exploit likelihood)

0.4%

Higher than 31.9% of all scored CVEs

Exploited in the wild

Yes

4 catalog listings

Public exploit code

Available

Proof-of-concept or weaponized module

Get the full CVE-2026-81963 brief as a PDF

Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.

Description

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

Known-Exploited Catalog Listings

Catalog	Added	Remediation due	Ransomware use
CISA KEV	Sep 8, 2026	Sep 22, 2026	Not reported
Industry KEV feed	Sep 8, 2026	Sep 22, 2026	Not reported
CIRCL KEV	Sep 8, 2026	Sep 22, 2026	Not reported
ENISA EUVD	Sep 8, 2026	n/a	Not reported

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.

Affected Products

35 affected entries in total

Product	Affected versions	Fixed in
windows 11 23H2Microsoft	10.0.22631.7582	10.0.22631.7582
windows 11 24H2Microsoft	10.0.26100.9445	10.0.26100.9445
windows 11 25H2Microsoft	10.0.26200.9445	10.0.26200.9445
windows 11 26H1Microsoft	10.0.28000.2954	10.0.28000.2954
Windows Server 2025Microsoft	10.0.26100.33438, >= 10.0.26100.0	10.0.26100.33438

5 more affected products in the full CVE brief

Patched Releases

windows 11 23H2

10.0.22631.7582

windows 11 24H2

10.0.26100.9445

windows 11 25H2

10.0.26200.9445

windows 11 26H1

10.0.28000.2954

Windows Server 2025

10.0.26100.33438

Windows 11 Version 23H2

10.0.22631.7582

Windows 11 Version 24H2

10.0.26100.9445

Windows 11 Version 25H2

10.0.26200.9445

Windows 11 version 26H1

10.0.28000.2954

Windows Server 2025 (Server Core installation)

10.0.26100.33438

Timeline

Publicly disclosed
Sep 8, 2026
Added to CISA KEV
Sep 8, 2026
Added to Industry KEV feed
Sep 8, 2026
Added to CIRCL KEV
Sep 8, 2026
Added to ENISA EUVD
Sep 8, 2026
Last updated
Oct 14, 2026

Weakness Type

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

References

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability
advisory5122871
advisory5122880
advisory5124008
advisory5124012

9 more references in the full CVE brief

FAQ

Common Questions.

Improper link resolution before file access ('link following') in Windows Update Stack allows an authorized attacker to elevate privileges locally.
Affected: windows 11 23H2 (Microsoft) versions 10.0.22631.7582; windows 11 24H2 (Microsoft) versions 10.0.26100.9445; windows 11 25H2 (Microsoft) versions 10.0.26200.9445, among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Sep 8, 2026.
Yes. It was added on Sep 8, 2026 with a federal remediation due date of Sep 22, 2026.
Public exploit code is available.
Fixed versions are available, including windows 11 23H2 10.0.22631.7582, windows 11 24H2 10.0.26100.9445, windows 11 25H2 10.0.26200.9445.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.

Is CVE-2026-81963 Running On Your Attack Surface?

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